kernel/linux.git/arch/powerpc/include/asm/kvm_host.h, branch linux-4.16.y

KVM: PPC: Book3S: Add MMIO emulation for VMX instructions

2018-02-09T05:51:51+00:00

This patch provides the MMIO load/store vector indexed X-Form emulation. Instructions implemented: lvx: the quadword in storage addressed by the result of EA & 0xffff_ffff_ffff_fff0 is loaded into VRT. stvx: the contents of VRS are stored into the quadword in storage addressed by the result of EA & 0xffff_ffff_ffff_fff0. Reported-by: Gopesh Kumar Chaudhary Reported-by: Balamuruhan S Signed-off-by: Jose Ricardo Ziviani Signed-off-by: Paul Mackerras

KVM: PPC: Book3S HV: Keep XIVE escalation interrupt masked unless ceded

2018-01-19T01:10:21+00:00

This works on top of the single escalation support. When in single escalation, with this change, we will keep the escalation interrupt disabled unless the VCPU is in H_CEDE (idle). In any other case, we know the VCPU will be rescheduled and thus there is no need to take escalation interrupts in the host whenever a guest interrupt fires. Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Paul Mackerras

KVM: PPC: Book3S HV: Make xive_pushed a byte, not a word

2018-01-19T01:10:21+00:00

Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Paul Mackerras

KVM: PPC: Book3S HV: Don't use existing "prodded" flag for XIVE escalations

2018-01-19T01:10:21+00:00

The prodded flag is only cleared at the beginning of H_CEDE, so every time we have an escalation, we will cause the *next* H_CEDE to return immediately. Instead use a dedicated "irq_pending" flag to indicate that a guest interrupt is pending for the VCPU. We don't reuse the existing exception bitmap so as to avoid expensive atomic ops. Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Paul Mackerras

KVM: PPC: Book3S HV: Allow for running POWER9 host in single-threaded mode

2017-11-01T04:36:35+00:00

This patch allows for a mode on POWER9 hosts where we control all the threads of a core, much as we do on POWER8. The mode is controlled by a module parameter on the kvm_hv module, called "indep_threads_mode". The normal mode on POWER9 is the "independent threads" mode, with indep_threads_mode=Y, where the host is in SMT4 mode (or in fact any desired SMT mode) and each thread independently enters and exits from KVM guests without reference to what other threads in the core are doing. If indep_threads_mode is set to N at the point when a VM is started, KVM will expect every core that the guest runs on to be in single threaded mode (that is, threads 1, 2 and 3 offline), and will set the flag that prevents secondary threads from coming online. We can still use all four threads; the code that implements dynamic micro-threading on POWER8 will become active in over-commit situations and will allow up to three other VCPUs to be run on the secondary threads of the core whenever a VCPU is run. The reason for wanting this mode is that this will allow us to run HPT guests on a radix host on a POWER9 machine that does not support "mixed mode", that is, having some threads in a core be in HPT mode while other threads are in radix mode. It will also make it possible to implement a "strict threads" mode in future, if desired. Signed-off-by: Paul Mackerras

KVM: PPC: Book3S HV: Unify dirty page map between HPT and radix

2017-11-01T04:36:21+00:00

Currently, the HPT code in HV KVM maintains a dirty bit per guest page in the rmap array, whether or not dirty page tracking has been enabled for the memory slot. In contrast, the radix code maintains a dirty bit per guest page in memslot->dirty_bitmap, and only does so when dirty page tracking has been enabled. This changes the HPT code to maintain the dirty bits in the memslot dirty_bitmap like radix does. This results in slightly less code overall, and will mean that we do not lose the dirty bits when transitioning between HPT and radix mode in future. There is one minor change to behaviour as a result. With HPT, when dirty tracking was enabled for a memslot, we would previously clear all the dirty bits at that point (both in the HPT entries and in the rmap arrays), meaning that a KVM_GET_DIRTY_LOG ioctl immediately following would show no pages as dirty (assuming no vcpus have run in the meantime). With this change, the dirty bits on HPT entries are not cleared at the point where dirty tracking is enabled, so KVM_GET_DIRTY_LOG would show as dirty any guest pages that are resident in the HPT and dirty. This is consistent with what happens on radix. This also fixes a bug in the mark_pages_dirty() function for radix (in the sense that the function no longer exists). In the case where a large page of 64 normal pages or more is marked dirty, the addressing of the dirty bitmap was incorrect and could write past the end of the bitmap. Fortunately this case was never hit in practice because a 2MB large page is only 32 x 64kB pages, and we don't support backing the guest with 1GB huge pages at this point. Signed-off-by: Paul Mackerras

KVM: PPC: Book3S HV: Rename hpte_setup_done to mmu_ready

2017-11-01T04:36:12+00:00

This renames the kvm->arch.hpte_setup_done field to mmu_ready because we will want to use it for radix guests too -- both for setting things up before vcpu execution, and for excluding vcpus from executing while MMU-related things get changed, such as in future switching the MMU from radix to HPT mode or vice-versa. This also moves the call to kvmppc_setup_partition_table() that was done in kvmppc_hv_setup_htab_rma() for HPT guests, and the setting of mmu_ready, into the caller in kvmppc_vcpu_run_hv(). Signed-off-by: Paul Mackerras

KVM: update to new mmu_notifier semantic v2

2017-08-31T23:13:00+00:00

Calls to mmu_notifier_invalidate_page() were replaced by calls to mmu_notifier_invalidate_range() and are now bracketed by calls to mmu_notifier_invalidate_range_start()/end() Remove now useless invalidate_page callback. Changed since v1 (Linus Torvalds) - remove now useless kvm_arch_mmu_notifier_invalidate_page() Signed-off-by: Jérôme Glisse Tested-by: Mike Galbraith Tested-by: Adam Borowski Cc: Paolo Bonzini Cc: Radim Krčmář Cc: kvm@vger.kernel.org Cc: Kirill A. Shutemov Cc: Andrew Morton Cc: Andrea Arcangeli Signed-off-by: Linus Torvalds

Merge branch 'kvm-ppc-next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD

2017-07-03T08:41:59+00:00

- Better machine check handling for HV KVM - Ability to support guests with threads=2, 4 or 8 on POWER9 - Fix for a race that could cause delayed recognition of signals - Fix for a bug where POWER9 guests could sleep with interrupts pending.

KVM: PPC: Book3S HV: Exit guest upon MCE when FWNMI capability is enabled

2017-06-22T01:24:57+00:00

Enhance KVM to cause a guest exit with KVM_EXIT_NMI exit reason upon a machine check exception (MCE) in the guest address space if the KVM_CAP_PPC_FWNMI capability is enabled (instead of delivering a 0x200 interrupt to guest). This enables QEMU to build error log and deliver machine check exception to guest via guest registered machine check handler. This approach simplifies the delivery of machine check exception to guest OS compared to the earlier approach of KVM directly invoking 0x200 guest interrupt vector. This design/approach is based on the feedback for the QEMU patches to handle machine check exception. Details of earlier approach of handling machine check exception in QEMU and related discussions can be found at: https://lists.nongnu.org/archive/html/qemu-devel/2014-11/msg00813.html Note: This patch now directly invokes machine_check_print_event_info() from kvmppc_handle_exit_hv() to print the event to host console at the time of guest exit before the exception is passed on to the guest. Hence, the host-side handling which was performed earlier via machine_check_fwnmi is removed. The reasons for this approach is (i) it is not possible to distinguish whether the exception occurred in the guest or the host from the pt_regs passed on the machine_check_exception(). Hence machine_check_exception() calls panic, instead of passing on the exception to the guest, if the machine check exception is not recoverable. (ii) the approach introduced in this patch gives opportunity to the host kernel to perform actions in virtual mode before passing on the exception to the guest. This approach does not require complex tweaks to machine_check_fwnmi and friends. Signed-off-by: Aravinda Prasad Reviewed-by: David Gibson Signed-off-by: Mahesh Salgaonkar Signed-off-by: Paul Mackerras