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2015-04-13Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds3-17/+6
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm changes from Ingo Molnar: "There were lots of changes in this development cycle: - over 100 separate cleanups, restructuring changes, speedups and fixes in the x86 system call, irq, trap and other entry code, part of a heroic effort to deobfuscate a decade old spaghetti asm code and its C code dependencies (Denys Vlasenko, Andy Lutomirski) - alternatives code fixes and enhancements (Borislav Petkov) - simplifications and cleanups to the compat code (Brian Gerst) - signal handling fixes and new x86 testcases (Andy Lutomirski) - various other fixes and cleanups By their nature many of these changes are risky - we tried to test them well on many different x86 systems (there are no known regressions), and they are split up finely to help bisection - but there's still a fair bit of residual risk left so caveat emptor" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (148 commits) perf/x86/64: Report regs_user->ax too in get_regs_user() perf/x86/64: Simplify regs_user->abi setting code in get_regs_user() perf/x86/64: Do report user_regs->cx while we are in syscall, in get_regs_user() perf/x86/64: Do not guess user_regs->cs, ss, sp in get_regs_user() x86/asm/entry/32: Tidy up JNZ instructions after TESTs x86/asm/entry/64: Reduce padding in execve stubs x86/asm/entry/64: Remove GET_THREAD_INFO() in ret_from_fork x86/asm/entry/64: Simplify jumps in ret_from_fork x86/asm/entry/64: Remove a redundant jump x86/asm/entry/64: Optimize [v]fork/clone stubs x86/asm/entry: Zero EXTRA_REGS for stub32_execve() too x86/asm/entry/64: Move stub_x32_execvecloser() to stub_execveat() x86/asm/entry/64: Use common code for rt_sigreturn() epilogue x86/asm/entry/64: Add forgotten CFI annotation x86/asm/entry/irq: Simplify interrupt dispatch table (IDT) layout x86/asm/entry/64: Move opportunistic sysret code to syscall code path x86, selftests: Add sigreturn selftest x86/alternatives: Guard NOPs optimization x86/asm/entry: Clear EXTRA_REGS for all executable formats x86/signal: Remove pax argument from restore_sigcontext ...
2015-04-13Merge branch 'timers-core-for-linus' of ↵Linus Torvalds1-7/+4
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Ingo Molnar: "The main changes in this cycle were: - clockevents state machine cleanups and enhancements (Viresh Kumar) - clockevents broadcast notifier horror to state machine conversion and related cleanups (Thomas Gleixner, Rafael J Wysocki) - clocksource and timekeeping core updates (John Stultz) - clocksource driver updates and fixes (Ben Dooks, Dmitry Osipenko, Hans de Goede, Laurent Pinchart, Maxime Ripard, Xunlei Pang) - y2038 fixes (Xunlei Pang, John Stultz) - NMI-safe ktime_get_raw_fast() and general refactoring of the clock code, in preparation to perf's per event clock ID support (Peter Zijlstra) - generic sched/clock fixes, optimizations and cleanups (Daniel Thompson) - clockevents cpu_down() race fix (Preeti U Murthy)" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (94 commits) timers/PM: Drop unnecessary braces from tick_freeze() timers/PM: Fix up tick_unfreeze() timekeeping: Get rid of stale comment clockevents: Cleanup dead cpu explicitely clockevents: Make tick handover explicit clockevents: Remove broadcast oneshot control leftovers sched/idle: Use explicit broadcast oneshot control function ARM: Tegra: Use explicit broadcast oneshot control function ARM: OMAP: Use explicit broadcast oneshot control function intel_idle: Use explicit broadcast oneshot control function ACPI/idle: Use explicit broadcast control function ACPI/PAD: Use explicit broadcast oneshot control function x86/amd/idle, clockevents: Use explicit broadcast oneshot control functions clockevents: Provide explicit broadcast oneshot control functions clockevents: Remove the broadcast control leftovers ARM: OMAP: Use explicit broadcast control function intel_idle: Use explicit broadcast control function cpuidle: Use explicit broadcast control function ACPI/processor: Use explicit broadcast control function ACPI/PAD: Use explicit broadcast control function ...
2015-04-08Merge tag 'v4.0-rc7' into x86/asm, to resolve conflictsIngo Molnar1-1/+9
Conflicts: arch/x86/kernel/entry_64.S Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-02x86/cpu: Factor out common CPU initialization code, fix 32-bit Xen PV guestsBoris Ostrovsky1-12/+1
Some of x86 bare-metal and Xen CPU initialization code is common between the two and therefore can be factored out to avoid code duplication. As a side effect, doing so will also extend the fix provided by commit a7fcf28d431e ("x86/asm/entry: Replace this_cpu_sp0() with current_top_of_stack() to x86_32") to 32-bit Xen PV guests. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: konrad.wilk@oracle.com Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1427897534-5086-1-git-send-email-boris.ostrovsky@oracle.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-01tick/xen: Provide and use tick_suspend_local() and tick_resume_local()Thomas Gleixner1-1/+1
Xen calls on every cpu into tick_resume() which is just wrong. tick_resume() is for the syscore global suspend/resume invocation. What XEN really wants is a per cpu local resume function. Provide a tick_resume_local() function and use it in XEN. Also provide a complementary tick_suspend_local() and modify tick_unfreeze() and tick_freeze(), respectively, to use the new local tick resume/suspend functions. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ Combined two patches, rebased, modified subject/changelog. ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1698741.eezk9tnXtG@vostro.rjw.lan [ Merged to latest timers/core. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-01clockevents: Make suspend/resume calls explicitThomas Gleixner1-7/+4
clockevents_notify() is a leftover from the early design of the clockevents facility. It's really not a notification mechanism, it's a multiplex call. We are way better off to have explicit calls instead of this monstrosity. Split out the suspend/resume() calls and invoke them directly from the call sites. No locking required at this point because these calls happen with interrupts disabled and a single cpu online. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ Rebased on top of 4.0-rc5. ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/713674030.jVm1qaHuPf@vostro.rjw.lan [ Rebased on top of latest timers/core. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-24x86/asm/entry: Get rid of KERNEL_STACK_OFFSETDenys Vlasenko1-2/+1
PER_CPU_VAR(kernel_stack) was set up in a way where it points five stack slots below the top of stack. Presumably, it was done to avoid one "sub $5*8,%rsp" in syscall/sysenter code paths, where iret frame needs to be created by hand. Ironically, none of them benefits from this optimization, since all of them need to allocate additional data on stack (struct pt_regs), so they still have to perform subtraction. This patch eliminates KERNEL_STACK_OFFSET. PER_CPU_VAR(kernel_stack) now points directly to top of stack. pt_regs allocations are adjusted to allocate iret frame as well. Hopefully we can merge it later with 32-bit specific PER_CPU_VAR(cpu_current_top_of_stack) variable... Net result in generated code is that constants in several insns are changed. This change is necessary for changing struct pt_regs creation in SYSCALL64 code path from MOV to PUSH instructions. Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Acked-by: Borislav Petkov <bp@suse.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/1426785469-15125-2-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23x86/xen: prepare p2m list for memory hotplugJuergen Gross1-1/+9
Commit 054954eb051f35e74b75a566a96fe756015352c8 ("xen: switch to linear virtual mapped sparse p2m list") introduced a regression regarding to memory hotplug for a pv-domain: as the virtual space for the p2m list is allocated for the to be expected memory size of the domain only, hotplugged memory above that size will not be usable by the domain. Correct this by using a configurable size for the p2m list in case of memory hotplug enabled (default supported memory size is 512 GB for 64 bit domains and 4 GB for 32 bit domains). Signed-off-by: Juergen Gross <jgross@suse.com> Cc: <stable@vger.kernel.org> # 3.19+ Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-03-23Merge tag 'v4.0-rc5' into x86/asm, to resolve conflictsIngo Molnar1-1/+1
Conflicts: arch/x86/kernel/entry_64.S Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-17x86/asm/entry/64: Rename 'old_rsp' to 'rsp_scratch'Ingo Molnar1-4/+4
Make clear that the usage of PER_CPU(old_rsp) is purely temporary, by renaming it to 'rsp_scratch'. Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-06x86/asm/entry: Add this_cpu_sp0() to read sp0 for the current cpuAndy Lutomirski1-0/+1
We currently store references to the top of the kernel stack in multiple places: kernel_stack (with an offset) and init_tss.x86_tss.sp0 (no offset). The latter is defined by hardware and is a clean canonical way to find the top of the stack. Add an accessor so we can start using it. This needs minor paravirt tweaks. On native, sp0 defines the top of the kernel stack and is therefore always correct. On Xen and lguest, the hypervisor tracks the top of the stack, but we want to start reading sp0 in the kernel. Fixing this is simple: just update our local copy of sp0 as well as the hypervisor's copy on task switches. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/8d675581859712bee09a055ed8f785d80dac1eca.1425611534.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-27x86/xen: correct bug in p2m list initializationJuergen Gross1-1/+1
Commit 054954eb051f35e74b75a566a96fe756015352c8 ("xen: switch to linear virtual mapped sparse p2m list") introduced an error. During initialization of the p2m list a p2m identity area mapped by a complete identity pmd entry has to be split up into smaller chunks sometimes, if a non-identity pfn is introduced in this area. If this non-identity pfn is not at index 0 of a p2m page the new p2m page needed is initialized with wrong identity entries, as the identity pfns don't start with the value corresponding to index 0, but with the initial non-identity pfn. This results in weird wrong mappings. Correct the wrong initialization by starting with the correct pfn. Cc: stable@vger.kernel.org # 3.19 Reported-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Juergen Gross <jgross@suse.com> Tested-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-02-23x86/xen: Initialize cr4 shadow for 64-bit PV(H) guestsBoris Ostrovsky1-0/+1
Commit 1e02ce4cccdc ("x86: Store a per-cpu shadow copy of CR4") introduced CR4 shadows. These shadows are initialized in early boot code. The commit missed initialization for 64-bit PV(H) guests that this patch adds. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-02-23x86/xen: Make sure X2APIC_ENABLE bit of MSR_IA32_APICBASE is not setBoris Ostrovsky1-1/+18
Commit d524165cb8db ("x86/apic: Check x2apic early") tests X2APIC_ENABLE bit of MSR_IA32_APICBASE when CONFIG_X86_X2APIC is off and panics the kernel when this bit is set. Xen's PV guests will pass this MSR read to the hypervisor which will return its version of the MSR, where this bit might be set. Make sure we clear it before returning MSR value to the caller. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-02-21Merge branch 'locking-urgent-for-linus' of ↵Linus Torvalds1-4/+9
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fixes from Ingo Molnar: "Two fixes: the paravirt spin_unlock() corruption/crash fix, and an rtmutex NULL dereference crash fix" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/spinlocks/paravirt: Fix memory corruption on unlock locking/rtmutex: Avoid a NULL pointer dereference on deadlock
2015-02-18x86/spinlocks/paravirt: Fix memory corruption on unlockRaghavendra K T1-4/+9
Paravirt spinlock clears slowpath flag after doing unlock. As explained by Linus currently it does: prev = *lock; add_smp(&lock->tickets.head, TICKET_LOCK_INC); /* add_smp() is a full mb() */ if (unlikely(lock->tickets.tail & TICKET_SLOWPATH_FLAG)) __ticket_unlock_slowpath(lock, prev); which is *exactly* the kind of things you cannot do with spinlocks, because after you've done the "add_smp()" and released the spinlock for the fast-path, you can't access the spinlock any more. Exactly because a fast-path lock might come in, and release the whole data structure. Linus suggested that we should not do any writes to lock after unlock(), and we can move slowpath clearing to fastpath lock. So this patch implements the fix with: 1. Moving slowpath flag to head (Oleg): Unlocked locks don't care about the slowpath flag; therefore we can keep it set after the last unlock, and clear it again on the first (try)lock. -- this removes the write after unlock. note that keeping slowpath flag would result in unnecessary kicks. By moving the slowpath flag from the tail to the head ticket we also avoid the need to access both the head and tail tickets on unlock. 2. use xadd to avoid read/write after unlock that checks the need for unlock_kick (Linus): We further avoid the need for a read-after-release by using xadd; the prev head value will include the slowpath flag and indicate if we need to do PV kicking of suspended spinners -- on modern chips xadd isn't (much) more expensive than an add + load. Result: setup: 16core (32 cpu +ht sandy bridge 8GB 16vcpu guest) benchmark overcommit %improve kernbench 1x -0.13 kernbench 2x 0.02 dbench 1x -1.77 dbench 2x -0.63 [Jeremy: Hinted missing TICKET_LOCK_INC for kick] [Oleg: Moved slowpath flag to head, ticket_equals idea] [PeterZ: Added detailed changelog] Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Jones <drjones@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Jones <davej@redhat.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Fernando Luis Vázquez Cao <fernando_b1@lab.ntt.co.jp> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ulrich Obergfell <uobergfe@redhat.com> Cc: Waiman Long <Waiman.Long@hp.com> Cc: a.ryabinin@samsung.com Cc: dave@stgolabs.net Cc: hpa@zytor.com Cc: jasowang@redhat.com Cc: jeremy@goop.org Cc: paul.gortmaker@windriver.com Cc: riel@redhat.com Cc: tglx@linutronix.de Cc: waiman.long@hp.com Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/20150215173043.GA7471@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-17Merge branch 'perf-core-for-linus' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 perf updates from Ingo Molnar: "This series tightens up RDPMC permissions: currently even highly sandboxed x86 execution environments (such as seccomp) have permission to execute RDPMC, which may leak various perf events / PMU state such as timing information and other CPU execution details. This 'all is allowed' RDPMC mode is still preserved as the (non-default) /sys/devices/cpu/rdpmc=2 setting. The new default is that RDPMC access is only allowed if a perf event is mmap-ed (which is needed to correctly interpret RDPMC counter values in any case). As a side effect of these changes CR4 handling is cleaned up in the x86 code and a shadow copy of the CR4 value is added. The extra CR4 manipulation adds ~ <50ns to the context switch cost between rdpmc-capable and rdpmc-non-capable mms" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86: Add /sys/devices/cpu/rdpmc=2 to allow rdpmc for all tasks perf/x86: Only allow rdpmc if a perf_event is mapped perf: Pass the event to arch_perf_update_userpage() perf: Add pmu callbacks to track event mapping and unmapping x86: Add a comment clarifying LDT context switching x86: Store a per-cpu shadow copy of CR4 x86: Clean up cr4 manipulation
2015-02-14Merge tag 'for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/borntraeger/linux Pull ACCESS_ONCE() rule tightening from Christian Borntraeger: "Tighten rules for ACCESS_ONCE This series tightens the rules for ACCESS_ONCE to only work on scalar types. It also contains the necessary fixups as indicated by build bots of linux-next. Now everything is in place to prevent new non-scalar users of ACCESS_ONCE and we can continue to convert code to READ_ONCE/WRITE_ONCE" * tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/borntraeger/linux: kernel: Fix sparse warning for ACCESS_ONCE next: sh: Fix compile error kernel: tighten rules for ACCESS ONCE mm/gup: Replace ACCESS_ONCE with READ_ONCE x86/spinlock: Leftover conversion ACCESS_ONCE->READ_ONCE x86/xen/p2m: Replace ACCESS_ONCE with READ_ONCE ppc/hugetlbfs: Replace ACCESS_ONCE with READ_ONCE ppc/kvm: Replace ACCESS_ONCE with READ_ONCE
2015-02-04x86: Clean up cr4 manipulationAndy Lutomirski1-2/+2
CR4 manipulation was split, seemingly at random, between direct (write_cr4) and using a helper (set/clear_in_cr4). Unfortunately, the set_in_cr4 and clear_in_cr4 helpers also poke at the boot code, which only a small subset of users actually wanted. This patch replaces all cr4 access in functions that don't leave cr4 exactly the way they found it with new helpers cr4_set_bits, cr4_clear_bits, and cr4_set_bits_and_update_boot. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Vince Weaver <vince@deater.net> Cc: "hillf.zj" <hillf.zj@alibaba-inc.com> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/495a10bdc9e67016b8fd3945700d46cfd5c12c2f.1414190806.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-28xen: mark grant mapped pages as foreignJennifer Herbert1-7/+0
Use the "foreign" page flag to mark pages that have a grant map. Use page->private to store information of the grant (the granting domain and the grant reference). Signed-off-by: Jennifer Herbert <jennifer.herbert@citrix.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-01-28x86/xen: require ballooned pages for grant mapsJennifer Herbert1-2/+3
Ballooned pages are always used for grant maps which means the original frame does not need to be saved in page->index nor restored after the grant unmap. This allows the workaround in netback for the conflicting use of the (unionized) page->index and page->pfmemalloc to be removed. Signed-off-by: Jennifer Herbert <jennifer.herbert@citrix.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-01-28xen: remove scratch frames for ballooned pages and m2p overrideDavid Vrabel1-246/+8
The scratch frame mappings for ballooned pages and the m2p override are broken. Remove them in preparation for replacing them with simpler mechanisms that works. The scratch pages did not ensure that the page was not in use. In particular, the foreign page could still be in use by hardware. If the guest reused the frame the hardware could read or write that frame. The m2p override did not handle the same frame being granted by two different grant references. Trying an M2P override lookup in this case is impossible. With the m2p override removed, the grant map/unmap for the kernel mappings (for x86 PV) can be easily batched in set_foreign_p2m_mapping() and clear_foreign_p2m_mapping(). Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2015-01-28xen/grant-table: pre-populate kernel unmap ops for xen_gnttab_unmap_refs()David Vrabel1-11/+10
When unmapping grants, instead of converting the kernel map ops to unmap ops on the fly, pre-populate the set of unmap ops. This allows the grant unmap for the kernel mappings to be trivially batched in the future. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2015-01-28x86/xen: cleanup arch/x86/xen/mmu.cJuergen Gross1-2/+0
Remove a nested ifdef. Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-01-28x86/xen: add some __init annotations in arch/x86/xen/mmu.cJuergen Gross1-7/+8
The file arch/x86/xen/mmu.c has some functions that can be annotated with "__init". Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-01-28x86/xen: add some __init and static annotations in arch/x86/xen/setup.cJuergen Gross1-3/+3
Some more functions in arch/x86/xen/setup.c can be made "__init". xen_ignore_unusable() can be made "static". Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-01-28x86/xen: use correct types for addresses in arch/x86/xen/setup.cJuergen Gross1-12/+13
In many places in arch/x86/xen/setup.c wrong types are used for physical addresses (u64 or unsigned long long). Use phys_addr_t instead. Use macros already defined instead of open coding them. Correct some other type mismatches. Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-01-28x86/xen: cleanup arch/x86/xen/setup.cJuergen Gross2-10/+6
Remove extern declarations in arch/x86/xen/setup.c which are either not used or redundant. Move needed other extern declarations to xen-ops.h Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-01-26x86,xen: use current->state helpersDavidlohr Bueso1-1/+1
Call __set_current_state() instead of assigning the new state directly. These interfaces also aid CONFIG_DEBUG_ATOMIC_SLEEP environments, keeping track of who changed the state. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-01-20x86/xen: prefer TSC over xen clocksource for dom0Palik, Imre1-0/+4
In Dom0's the use of the TSC clocksource (whenever it is stable enough to be used) instead of the Xen clocksource should not cause any issues, as Dom0 VMs never live-migrated. The TSC clocksource is somewhat more efficient than the Xen paravirtualised clocksource, thus it should have higher rating. This patch decreases the rating of the Xen clocksource in Dom0s to 275. Which is half-way between the rating of the TSC clocksource (300) and the hpet clocksource (250). Cc: Anthony Liguori <aliguori@amazon.com> Signed-off-by: Imre Palik <imrep@amazon.de> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-01-19x86/xen/p2m: Replace ACCESS_ONCE with READ_ONCEChristian Borntraeger1-1/+1
ACCESS_ONCE does not work reliably on non-scalar types. For example gcc 4.6 and 4.7 might remove the volatile tag for such accesses during the SRA (scalar replacement of aggregates) step (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145) Change the p2m code to replace ACCESS_ONCE with READ_ONCE. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Juergen Gross <jgross@suse.com> Acked-by: David Vrabel <david.vrabel@citrix.com>
2015-01-13Merge tag 'stable/for-linus-3.19-rc4-tag' of ↵Linus Torvalds4-46/+56
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen bug fixes from David Vrabel: "Several critical linear p2m fixes that prevented some hosts from booting" * tag 'stable/for-linus-3.19-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: x86/xen: properly retrieve NMI reason xen: check for zero sized area when invalidating memory xen: use correct type for physical addresses xen: correct race in alloc_p2m_pmd() xen: correct error for building p2m list on 32 bits x86/xen: avoid freeing static 'name' when kasprintf() fails x86/xen: add extra memory for remapped frames during setup x86/xen: don't count how many PFNs are identity mapped x86/xen: Free bootmem in free_p2m_page() during early boot x86/xen: Remove unnecessary BUG_ON(preemptible()) in xen_setup_timer()
2015-01-13x86/xen: properly retrieve NMI reasonJan Beulich1-1/+21
Using the native code here can't work properly, as the hypervisor would normally have cleared the two reason bits by the time Dom0 gets to see the NMI (if passed to it at all). There's a shared info field for this, and there's an existing hook to use - just fit the two together. This is particularly relevant so that NMIs intended to be handled by APEI / GHES actually make it to the respective handler. Note that the hook can (and should) be used irrespective of whether being in Dom0, as accessing port 0x61 in a DomU would be even worse, while the shared info field would just hold zero all the time. Note further that hardware NMI handling for PVH doesn't currently work anyway due to missing code in the hypervisor (but it is expected to work the native rather than the PV way). Signed-off-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-01-12xen: check for zero sized area when invalidating memoryJuergen Gross1-0/+2
With the introduction of the linear mapped p2m list setting memory areas to "invalid" had to be delayed. When doing the invalidation make sure no zero sized areas are processed. Signed-off-by: Juegren Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-01-12xen: use correct type for physical addressesJuergen Gross1-2/+2
When converting a pfn to a physical address be sure to use 64 bit wide types or convert the physical address to a pfn if possible. Signed-off-by: Juergen Gross <jgross@suse.com> Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-01-12xen: correct race in alloc_p2m_pmd()Juergen Gross1-6/+3
When allocating a new pmd for the linear mapped p2m list a check is done for not introducing another pmd when this just happened on another cpu. In this case the old pte pointer was returned which points to the p2m_missing or p2m_identity page. The correct value would be the pointer to the found new page. Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-01-12xen: correct error for building p2m list on 32 bitsJuergen Gross1-1/+1
In xen_rebuild_p2m_list() for large areas of invalid or identity mapped memory the pmd entries on 32 bit systems are initialized wrong. Correct this error. Suggested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-01-08x86/xen: avoid freeing static 'name' when kasprintf() failsVitaly Kuznetsov1-11/+5
In case kasprintf() fails in xen_setup_timer() we assign name to the static string "<timer kasprintf failed>". We, however, don't check that fact before issuing kfree() in xen_teardown_timer(), kernel is supposed to crash with 'kernel BUG at mm/slub.c:3341!' Solve the issue by making name a fixed length string inside struct xen_clock_event_device. 16 bytes should be enough. Suggested-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-01-08x86/xen: add extra memory for remapped frames during setupDavid Vrabel1-4/+9
If the non-RAM regions in the e820 memory map are larger than the size of the initial balloon, a BUG was triggered as the frames are remaped beyond the limit of the linear p2m. The frames are remapped into the initial balloon area (xen_extra_mem) but not enough of this is available. Ensure enough extra memory regions are added for these remapped frames. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Juergen Gross <jgross@suse.com>
2015-01-08x86/xen: don't count how many PFNs are identity mappedDavid Vrabel1-18/+9
This accounting is just used to print a diagnostic message that isn't very useful. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Juergen Gross <jgross@suse.com>
2015-01-08x86/xen: Free bootmem in free_p2m_page() during early bootBoris Ostrovsky1-3/+6
With recent changes in p2m we now have legitimate cases when p2m memory needs to be freed during early boot (i.e. before slab is initialized). Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-12-23x86/xen: Remove unnecessary BUG_ON(preemptible()) in xen_setup_timer()Boris Ostrovsky1-2/+0
There is no reason for having it and, with commit 250a1ac685f1 ("x86, smpboot: Remove pointless preempt_disable() in native_smp_prepare_cpus()"), it prevents HVM guests from booting. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-12-17Merge tag 'stable/for-linus-3.19-rc0b-tag' of ↵Linus Torvalds4-951/+708
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull additional xen update from David Vrabel: "Xen: additional features for 3.19-rc0 - Linear p2m for x86 PV guests which simplifies the p2m code, improves performance and will allow for > 512 GB PV guests in the future. A last-minute, configuration specific issue was discovered with this change which is why it was not included in my previous pull request. This is now been fixed and tested" * tag 'stable/for-linus-3.19-rc0b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen: switch to post-init routines in xen mmu.c earlier Revert "swiotlb-xen: pass dev_addr to swiotlb_tbl_unmap_single" xen: annotate xen_set_identity_and_remap_chunk() with __init xen: introduce helper functions to do safe read and write accesses xen: Speed up set_phys_to_machine() by using read-only mappings xen: switch to linear virtual mapped sparse p2m list xen: Hide get_phys_to_machine() to be able to tune common path x86: Introduce function to get pmd entry pointer xen: Delay invalidating extra memory xen: Delay m2p_override initialization xen: Delay remapping memory of pv-domain xen: use common page allocation function in p2m.c xen: Make functions static xen: fix some style issues in p2m.c
2014-12-11xen: switch to post-init routines in xen mmu.c earlierJuergen Gross1-1/+1
With the virtual mapped linear p2m list the post-init mmu operations must be used for setting up the p2m mappings, as in case of CONFIG_FLATMEM the init routines may trigger BUGs. paging_init() sets up all infrastructure needed to switch to the post-init mmu ops done by xen_post_allocator_init(). With the virtual mapped linear p2m list we need some mmu ops during setup of this list, so we have to switch to the correct mmu ops as soon as possible. The p2m list is usable from the beginning, just expansion requires to have established the new linear mapping. So the call of xen_remap_memory() had to be introduced, but this is not due to the mmu ops requiring this. Summing it up: calling xen_post_allocator_init() not directly after paging_init() was conceptually wrong in the beginning, it just didn't matter up to now as no functions used between the two calls needed some critical mmu ops (e.g. alloc_pte). This has changed now, so I corrected it. Reported-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-12-11Merge branch 'x86-vdso-for-linus' of ↵Linus Torvalds1-2/+4
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 vdso updates from Ingo Molnar: "Various vDSO updates from Andy Lutomirski, mostly cleanups and reorganization to improve maintainability, but also some micro-optimizations and robustization changes" * 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86_64/vsyscall: Restore orig_ax after vsyscall seccomp x86_64: Add a comment explaining the TASK_SIZE_MAX guard page x86_64,vsyscall: Make vsyscall emulation configurable x86_64, vsyscall: Rewrite comment and clean up headers in vsyscall code x86_64, vsyscall: Turn vsyscalls all the way off when vsyscall==none x86,vdso: Use LSL unconditionally for vgetcpu x86: vdso: Fix build with older gcc x86_64/vdso: Clean up vgetcpu init and merge the vdso initcalls x86_64/vdso: Remove jiffies from the vvar page x86/vdso: Make the PER_CPU segment 32 bits x86/vdso: Make the PER_CPU segment start out accessed x86/vdso: Change the PER_CPU segment to use struct desc_struct x86_64/vdso: Move getcpu code from vsyscall_64.c to vdso/vma.c x86_64/vsyscall: Move all of the gate_area code to vsyscall_64.c
2014-12-11Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds3-65/+8
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm tree changes from Ingo Molnar: "The biggest change is full PAT support from Jürgen Gross: The x86 architecture offers via the PAT (Page Attribute Table) a way to specify different caching modes in page table entries. The PAT MSR contains 8 entries each specifying one of 6 possible cache modes. A pte references one of those entries via 3 bits: _PAGE_PAT, _PAGE_PWT and _PAGE_PCD. The Linux kernel currently supports only 4 different cache modes. The PAT MSR is set up in a way that the setting of _PAGE_PAT in a pte doesn't matter: the top 4 entries in the PAT MSR are the same as the 4 lower entries. This results in the kernel not supporting e.g. write-through mode. Especially this cache mode would speed up drivers of video cards which now have to use uncached accesses. OTOH some old processors (Pentium) don't support PAT correctly and the Xen hypervisor has been using a different PAT MSR configuration for some time now and can't change that as this setting is part of the ABI. This patch set abstracts the cache mode from the pte and introduces tables to translate between cache mode and pte bits (the default cache mode "write back" is hard-wired to PAT entry 0). The tables are statically initialized with values being compatible to old processors and current usage. As soon as the PAT MSR is changed (or - in case of Xen - is read at boot time) the tables are changed accordingly. Requests of mappings with special cache modes are always possible now, in case they are not supported there will be a fallback to a compatible but slower mode. Summing it up, this patch set adds the following features: - capability to support WT and WP cache modes on processors with full PAT support - processors with no or uncorrect PAT support are still working as today, even if WT or WP cache mode are selected by drivers for some pages - reduction of Xen special handling regarding cache mode Another change is a boot speedup on ridiculously large RAM systems, plus other smaller fixes" * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits) x86: mm: Move PAT only functions to mm/pat.c xen: Support Xen pv-domains using PAT x86: Enable PAT to use cache mode translation tables x86: Respect PAT bit when copying pte values between large and normal pages x86: Support PAT bit in pagetable dump for lower levels x86: Clean up pgtable_types.h x86: Use new cache mode type in memtype related functions x86: Use new cache mode type in mm/ioremap.c x86: Use new cache mode type in setting page attributes x86: Remove looking for setting of _PAGE_PAT_LARGE in pageattr.c x86: Use new cache mode type in track_pfn_remap() and track_pfn_insert() x86: Use new cache mode type in mm/iomap_32.c x86: Use new cache mode type in asm/pgtable.h x86: Use new cache mode type in arch/x86/mm/init_64.c x86: Use new cache mode type in arch/x86/pci x86: Use new cache mode type in drivers/video/fbdev/vermilion x86: Use new cache mode type in drivers/video/fbdev/gbefb.c x86: Use new cache mode type in include/asm/fb.h x86: Make page cache mode a real type x86: mm: Use 2GB memory block size on large-memory x86-64 systems ...
2014-12-08xen: annotate xen_set_identity_and_remap_chunk() with __initJuergen Gross1-1/+1
Commit 5b8e7d80542487ff1bf17b4cf2922a01dee13d3a removed the __init annotation from xen_set_identity_and_remap_chunk(). Add it again. Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-12-08xen: introduce helper functions to do safe read and write accessesJuergen Gross1-1/+1
Introduce two helper functions to safely read and write unsigned long values from or to memory when the access may fault because the mapping is non-present or read-only. These helpers can be used instead of open coded uses of __get_user() and __put_user() avoiding the need to do casts to fix sparse warnings. Use the helpers in page.h and p2m.c. This will fix the sparse warnings when doing "make C=1". Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-12-04xen: Speed up set_phys_to_machine() by using read-only mappingsJuergen Gross1-6/+8
Instead of checking at each call of set_phys_to_machine() whether a new p2m page has to be allocated due to writing an entry in a large invalid or identity area, just map those areas read only and react to a page fault on write by allocating the new page. This change will make the common path with no allocation much faster as it only requires a single write of the new mfn instead of walking the address translation tables and checking for the special cases. Suggested-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-12-04xen: switch to linear virtual mapped sparse p2m listJuergen Gross3-440/+331
At start of the day the Xen hypervisor presents a contiguous mfn list to a pv-domain. In order to support sparse memory this mfn list is accessed via a three level p2m tree built early in the boot process. Whenever the system needs the mfn associated with a pfn this tree is used to find the mfn. Instead of using a software walked tree for accessing a specific mfn list entry this patch is creating a virtual address area for the entire possible mfn list including memory holes. The holes are covered by mapping a pre-defined page consisting only of "invalid mfn" entries. Access to a mfn entry is possible by just using the virtual base address of the mfn list and the pfn as index into that list. This speeds up the (hot) path of determining the mfn of a pfn. Kernel build on a Dell Latitude E6440 (2 cores, HT) in 64 bit Dom0 showed following improvements: Elapsed time: 32:50 -> 32:35 System: 18:07 -> 17:47 User: 104:00 -> 103:30 Tested with following configurations: - 64 bit dom0, 8GB RAM - 64 bit dom0, 128 GB RAM, PCI-area above 4 GB - 32 bit domU, 512 MB, 8 GB, 43 GB (more wouldn't work even without the patch) - 32 bit domU, ballooning up and down - 32 bit domU, save and restore - 32 bit domU with PCI passthrough - 64 bit domU, 8 GB, 2049 MB, 5000 MB - 64 bit domU, ballooning up and down - 64 bit domU, save and restore - 64 bit domU with PCI passthrough Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>