summaryrefslogtreecommitdiff
path: root/arch/x86/kvm/emulate.c
AgeCommit message (Collapse)AuthorFilesLines
2018-09-26kvm: x86: use correct privilege level for sgdt/sidt/fxsave/fxrstor accessPaolo Bonzini1-6/+6
commit 3c9fa24ca7c9c47605672916491f79e8ccacb9e6 upstream. The functions that were used in the emulation of fxrstor, fxsave, sgdt and sidt were originally meant for task switching, and as such they did not check privilege levels. This is very bad when the same functions are used in the emulation of unprivileged instructions. This is CVE-2018-10853. The obvious fix is to add a new argument to ops->read_std and ops->write_std, which decides whether the access is a "system" access or should use the processor's CPL. Fixes: 129a72a0d3c8 ("KVM: x86: Introduce segmented_write_std", 2017-01-12) Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [bwh: Backported to 3.16: Drop change in handle_ud()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2018-09-26KVM: x86: introduce linear_{read,write}_systemPaolo Bonzini1-32/+32
commit 79367a65743975e5cac8d24d08eccc7fdae832b0 upstream. Wrap the common invocation of ctxt->ops->read_std and ctxt->ops->write_std, so as to have a smaller patch when the functions grow another argument. Fixes: 129a72a0d3c8 ("KVM: x86: Introduce segmented_write_std", 2017-01-12) Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2018-09-26KVM: x86: Emulator ignores LDTR/TR extended base on LLDT/LTRNadav Amit1-1/+7
commit e37a75a13cdae5deaa2ea2cbf8d55b5dd08638b6 upstream. The current implementation ignores the LDTR/TR base high 32-bits on long-mode. As a result the loaded segment descriptor may be incorrect. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2018-03-19KVM: x86: Make indirect calls in emulator speculation safePeter Zijlstra1-4/+5
commit 1a29b5b7f347a1a9230c1e0af5b37e3e571588ab upstream. Replace the indirect calls with CALL_NOSPEC. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ashok Raj <ashok.raj@intel.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Jun Nakajima <jun.nakajima@intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: rga@amazon.de Cc: Dave Hansen <dave.hansen@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jason Baron <jbaron@akamai.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Link: https://lkml.kernel.org/r/20180125095843.595615683@infradead.org [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-07-02KVM: x86: fix singlestepping over syscallPaolo Bonzini1-0/+1
commit c8401dda2f0a00cd25c0af6a95ed50e478d25de4 upstream. TF is handled a bit differently for syscall and sysret, compared to the other instructions: TF is checked after the instruction completes, so that the OS can disable #DB at a syscall by adding TF to FMASK. When the sysret is executed the #DB is taken "as if" the syscall insn just completed. KVM emulates syscall so that it can trap 32-bit syscall on Intel processors. Fix the behavior, otherwise you could get #DB on a user stack which is not nice. This does not affect Linux guests, as they use an IST or task gate for #DB. This fixes CVE-2017-7518. Reported-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> [bwh: Backported to 3.16: - kvm_vcpu_check_singlestep() did not take an rflags parameter but called get_rflags() itself; delete that code - kvm_vcpu_check_singlestep() sets some flags differently - Drop changes to kvm_skip_emulated_instruction()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-02-26KVM: x86: Introduce segmented_write_stdSteve Rutherford1-2/+16
commit 129a72a0d3c8e139a04512325384fe5ac119e74d upstream. Introduces segemented_write_std. Switches from emulated reads/writes to standard read/writes in fxsave, fxrstor, sgdt, and sidt. This fixes CVE-2017-2584, a longstanding kernel memory leak. Since commit 283c95d0e389 ("KVM: x86: emulate FXSAVE and FXRSTOR", 2016-11-09), which is luckily not yet in any final release, this would also be an exploitable kernel memory *write*! Reported-by: Dmitry Vyukov <dvyukov@google.com> Fixes: 96051572c819194c37a8367624b285be10297eca Fixes: 283c95d0e3891b64087706b344a4b545d04a6e62 Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Steve Rutherford <srutherford@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [bwh: Backported to 3.16: drop changes to em_fxsave(), em_fxrstor()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-02-26KVM: x86: fix emulation of "MOV SS, null selector"Paolo Bonzini1-10/+38
commit 33ab91103b3415e12457e3104f0e4517ce12d0f3 upstream. This is CVE-2017-2583. On Intel this causes a failed vmentry because SS's type is neither 3 nor 7 (even though the manual says this check is only done for usable SS, and the dmesg splat says that SS is unusable!). On AMD it's worse: svm.c is confused and sets CPL to 0 in the vmcb. The fix fabricates a data segment descriptor when SS is set to a null selector, so that CPL and SS.DPL are set correctly in the VMCS/vmcb. Furthermore, only allow setting SS to a NULL selector if SS.RPL < 3; this in turn ensures CPL < 3 because RPL must be equal to CPL. Thanks to Andy Lutomirski and Willy Tarreau for help in analyzing the bug and deciphering the manuals. Reported-by: Xiaohan Zhang <zhangxiaohan1@huawei.com> Fixes: 79d5b4c3cd809c770d4bf9812635647016c56011 Cc: stable@nongnu.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-02-23KVM: x86: drop error recovery in em_jmp_far and em_ret_farRadim Krčmář1-25/+11
commit 2117d5398c81554fbf803f5fd1dc55eb78216c0c upstream. em_jmp_far and em_ret_far assumed that setting IP can only fail in 64 bit mode, but syzkaller proved otherwise (and SDM agrees). Code segment was restored upon failure, but it was left uninitialized outside of long mode, which could lead to a leak of host kernel stack. We could have fixed that by always saving and restoring the CS, but we take a simpler approach and just break any guest that manages to fail as the error recovery is error-prone and modern CPUs don't need emulator for this. Found by syzkaller: WARNING: CPU: 2 PID: 3668 at arch/x86/kvm/emulate.c:2217 em_ret_far+0x428/0x480 Kernel panic - not syncing: panic_on_warn set ... CPU: 2 PID: 3668 Comm: syz-executor Not tainted 4.9.0-rc4+ #49 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 [...] Call Trace: [...] __dump_stack lib/dump_stack.c:15 [...] dump_stack+0xb3/0x118 lib/dump_stack.c:51 [...] panic+0x1b7/0x3a3 kernel/panic.c:179 [...] __warn+0x1c4/0x1e0 kernel/panic.c:542 [...] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585 [...] em_ret_far+0x428/0x480 arch/x86/kvm/emulate.c:2217 [...] em_ret_far_imm+0x17/0x70 arch/x86/kvm/emulate.c:2227 [...] x86_emulate_insn+0x87a/0x3730 arch/x86/kvm/emulate.c:5294 [...] x86_emulate_instruction+0x520/0x1ba0 arch/x86/kvm/x86.c:5545 [...] emulate_instruction arch/x86/include/asm/kvm_host.h:1116 [...] complete_emulated_io arch/x86/kvm/x86.c:6870 [...] complete_emulated_mmio+0x4e9/0x710 arch/x86/kvm/x86.c:6934 [...] kvm_arch_vcpu_ioctl_run+0x3b7a/0x5a90 arch/x86/kvm/x86.c:6978 [...] kvm_vcpu_ioctl+0x61e/0xdd0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2557 [...] vfs_ioctl fs/ioctl.c:43 [...] do_vfs_ioctl+0x18c/0x1040 fs/ioctl.c:679 [...] SYSC_ioctl fs/ioctl.c:694 [...] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685 [...] entry_SYSCALL_64_fastpath+0x1f/0xc2 Reported-by: Dmitry Vyukov <dvyukov@google.com> Fixes: d1442d85cc30 ("KVM: x86: Handle errors when RIP is set during far jumps") Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-03-18KVM: emulate: fix CMPXCHG8B on 32-bit hostsPaolo Bonzini1-1/+2
commit 4ff6f8e61eb7f96d3ca535c6d240f863ccd6fb7d upstream. This has been broken for a long time: it broke first in 2.6.35, then was almost fixed in 2.6.36 but this one-liner slipped through the cracks. The bug shows up as an infinite loop in Windows 7 (and newer) boot on 32-bit hosts without EPT. Windows uses CMPXCHG8B to write to page tables, which causes a page fault if running without EPT; the emulator is then called from kvm_mmu_page_fault. The loop then happens if the higher 4 bytes are not 0; the common case for this is that the NX bit (bit 63) is 1. Fixes: 6550e1f165f384f3a46b60a1be9aba4bc3c2adad Fixes: 16518d5ada690643453eb0aef3cc7841d3623c2d Reported-by: Erik Rull <erik.rull@rdsoftware.de> Tested-by: Erik Rull <erik.rull@rdsoftware.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2015-02-04KVM: x86: SYSENTER emulation is brokenNadav Amit1-19/+8
commit f3747379accba8e95d70cec0eae0582c8c182050 upstream. SYSENTER emulation is broken in several ways: 1. It misses the case of 16-bit code segments completely (CVE-2015-0239). 2. MSR_IA32_SYSENTER_CS is checked in 64-bit mode incorrectly (bits 0 and 1 can still be set without causing #GP). 3. MSR_IA32_SYSENTER_EIP and MSR_IA32_SYSENTER_ESP are not masked in legacy-mode. 4. There is some unneeded code. Fix it. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [ luis: backported to 3.16: adjusted context ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2015-01-15KVM: x86: em_ret_far overrides cplNadav Amit1-1/+1
commit ab646f54f4fd1a8b9671b8707f0739fdd28ce2b1 upstream. commit d50eaa18039b ("KVM: x86: Perform limit checks when assigning EIP") mistakenly used zero as cpl on em_ret_far. Use the actual one. Fixes: d50eaa18039b8b848c2285478d0775335ad5e930 Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2014-11-20KVM: x86: Fix uninitialized op->type for some immediate valuesNadav Amit1-0/+8
commit d29b9d7ed76c0b961603ca692b8a562556a20212 upstream. The emulator could reuse an op->type from a previous instruction for some immediate values. If it mistakenly considers the operands as memory operands, it will performs a memory read and overwrite op->val. Consider for instance the ROR instruction - src2 (the number of times) would be read from memory instead of being used as immediate. Mark every immediate operand as such to avoid this problem. Fixes: c44b4c6ab80eef3a9c52c7b3f0c632942e6489aa Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2014-11-05KVM: x86: Fix far-jump to non-canonical checkNadav Amit1-3/+5
commit 7e46dddd6f6cd5dbf3c7bd04a7e75d19475ac9f2 upstream. Commit d1442d85cc30 ("KVM: x86: Handle errors when RIP is set during far jumps") introduced a bug that caused the fix to be incomplete. Due to incorrect evaluation, far jump to segment with L bit cleared (i.e., 32-bit segment) and RIP with any of the high bits set (i.e, RIP[63:32] != 0) set may not trigger #GP. As we know, this imposes a security problem. In addition, the condition for two warnings was incorrect. Fixes: d1442d85cc30ea75f7d399474ca738e0bc96f715 Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> [Add #ifdef CONFIG_X86_64 to avoid complaints of undefined behavior. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2014-11-05KVM: x86: Handle errors when RIP is set during far jumpsNadav Amit1-30/+88
commit d1442d85cc30ea75f7d399474ca738e0bc96f715 upstream. Far jmp/call/ret may fault while loading a new RIP. Currently KVM does not handle this case, and may result in failed vm-entry once the assignment is done. The tricky part of doing so is that loading the new CS affects the VMCS/VMCB state, so if we fail during loading the new RIP, we are left in unconsistent state. Therefore, this patch saves on 64-bit the old CS descriptor and restores it if loading RIP failed. This fixes CVE-2014-3647. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [ luis: backported to 3.16: adjusted context ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2014-11-05KVM: x86: Emulator fixes for eip canonical checks on near branchesNadav Amit1-24/+54
commit 234f3ce485d54017f15cf5e0699cff4100121601 upstream. Before changing rip (during jmp, call, ret, etc.) the target should be asserted to be canonical one, as real CPUs do. During sysret, both target rsp and rip should be canonical. If any of these values is noncanonical, a #GP exception should occur. The exception to this rule are syscall and sysenter instructions in which the assigned rip is checked during the assignment to the relevant MSRs. This patch fixes the emulator to behave as real CPUs do for near branches. Far branches are handled by the next patch. This fixes CVE-2014-3647. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2014-11-05KVM: x86: Fix wrong masking on relative jump/callNadav Amit1-5/+22
commit 05c83ec9b73c8124555b706f6af777b10adf0862 upstream. Relative jumps and calls do the masking according to the operand size, and not according to the address size as the KVM emulator does today. This patch fixes KVM behavior. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2014-09-06KVM: x86: Inter-privilege level ret emulation is not implemenetedNadav Amit1-0/+4
commit 9e8919ae793f4edfaa29694a70f71a515ae9942a upstream. Return unhandlable error on inter-privilege level ret instruction. This is since the current emulation does not check the privilege level correctly when loading the CS, and does not pop RSP/SS as needed. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27KVM: x86: MOV CR/DR emulation should ignore modNadav Amit1-5/+8
MOV CR/DR instructions ignore the mod field (in the ModR/M byte). As the SDM states: "The 2 bits in the mod field are ignored". Accordingly, the second operand of these instructions is always a general purpose register. The current emulator implementation does not do so. If the mod bits do not equal 3, it expects the second operand to be in memory. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-22KVM: x86: check CS.DPL against RPL during task switchPaolo Bonzini1-14/+17
Table 7-1 of the SDM mentions a check that the code segment's DPL must match the selector's RPL. This was not done by KVM, fix it. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-22KVM: x86: use new CS.RPL as CPL during task switchPaolo Bonzini1-27/+33
During task switch, all of CS.DPL, CS.RPL, SS.DPL must match (in addition to all the other requirements) and will be the new CPL. So far this worked by carefully setting the CS selector and flag before doing the task switch; setting CS.selector will already change the CPL. However, this will not work once we get the CPL from SS.DPL, because then you will have to set the full segment descriptor cache to change the CPL. ctxt->ops->cpl(ctxt) will then return the old CPL during the task switch, and the check that SS.DPL == CPL will fail. Temporarily assume that the CPL comes from CS.RPL during task switch to a protected-mode task. This is the same approach used in QEMU's emulation code, which (until version 2.0) manually tracks the CPL. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-04-24KVM: x86: IN instruction emulation should ignore REP-prefixNadav Amit1-1/+2
The IN instruction is not be affected by REP-prefix as INS is. Therefore, the emulation should ignore the REP prefix as well. The current emulator implementation tries to perform writeback when IN instruction with REP-prefix is emulated. This causes it to perform wrong memory write or spurious #GP exception to be injected to the guest. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-24KVM: x86: Fix CR3 reserved bitsNadav Amit1-4/+0
According to Intel specifications, PAE and non-PAE does not have any reserved bits. In long-mode, regardless to PCIDE, only the high bits (above the physical address) are reserved. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-22KVM: x86: Fix CR3 and LDT sel should not be saved in TSSNadav Amit1-4/+6
According to Intel specifications, only general purpose registers and segment selectors should be saved in the old TSS during 32-bit task-switch. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-03-17KVM: x86 emulator: emulate MOVAPDIgor Mammedov1-1/+1
Add emulation for 0x66 prefixed instruction of 0f 28 opcode that has been added earlier. Signed-off-by: Igor Mammedov <imammedo@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-03-17KVM: x86 emulator: emulate MOVAPSIgor Mammedov1-1/+7
HCK memory driver test fails when testing 32-bit Windows 8.1 with baloon driver. tracing KVM shows error: reason EXIT_ERR rip 0x81c18326 info 0 0 x/10i 0x81c18326-20 0x0000000081c18312: add %al,(%eax) 0x0000000081c18314: add %cl,-0x7127711d(%esi) 0x0000000081c1831a: rolb $0x0,0x80ec(%ecx) 0x0000000081c18321: and $0xfffffff0,%esp 0x0000000081c18324: mov %esp,%esi 0x0000000081c18326: movaps %xmm0,(%esi) 0x0000000081c18329: movaps %xmm1,0x10(%esi) 0x0000000081c1832d: movaps %xmm2,0x20(%esi) 0x0000000081c18331: movaps %xmm3,0x30(%esi) 0x0000000081c18335: movaps %xmm4,0x40(%esi) which points to MOVAPS instruction currently no emulated by KVM. Fix it by adding appropriate entries to opcode table in KVM's emulator. Signed-off-by: Igor Mammedov <imammedo@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-11-05KVM: emulator: cleanup decode_register_operand() a bitGleb Natapov1-7/+3
Make code shorter. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-11-05KVM: emulator: check rex prefix inside decode_register()Gleb Natapov1-11/+7
All decode_register() callers check if instruction has rex prefix to properly decode one byte operand. It make sense to move the check inside. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-11-03KVM: x86: fix emulation of "movzbl %bpl, %eax"Paolo Bonzini1-1/+4
When I was looking at RHEL5.9's failure to start with unrestricted_guest=0/emulate_invalid_guest_state=1, I got it working with a slightly older tree than kvm.git. I now debugged the remaining failure, which was introduced by commit 660696d1 (KVM: X86 emulator: fix source operand decoding for 8bit mov[zs]x instructions, 2013-04-24) introduced a similar mis-emulation to the one in commit 8acb4207 (KVM: fix sil/dil/bpl/spl in the mod/rm fields, 2013-05-30). The incorrect decoding occurs in 8-bit movzx/movsx instructions whose 8-bit operand is sil/dil/bpl/spl. Needless to say, "movzbl %bpl, %eax" does occur in RHEL5.9's decompression prolog, just a handful of instructions before finally giving control to the decompressed vmlinux and getting out of the invalid guest state. Because OpMem8 bypasses decode_modrm, the same handling of the REX prefix must be applied to OpMem8. Reported-by: Michele Baldessari <michele@redhat.com> Cc: stable@vger.kernel.org Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-11-01KVM: x86: emulate SAHF instructionPaolo Bonzini1-1/+14
Yet another instruction that we fail to emulate, this time found in Windows 2008R2 32-bit. Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-10-30kvm: Emulate MOVBEBorislav Petkov1-4/+49
This basically came from the need to be able to boot 32-bit Atom SMP guests on an AMD host, i.e. a host which doesn't support MOVBE. As a matter of fact, qemu has since recently received MOVBE support but we cannot share that with kvm emulation and thus we have to do this in the host. We're waay faster in kvm anyway. :-) So, we piggyback on the #UD path and emulate the MOVBE functionality. With it, an 8-core SMP guest boots in under 6 seconds. Also, requesting MOVBE emulation needs to happen explicitly to work, i.e. qemu -cpu n270,+movbe... Just FYI, a fairly straight-forward boot of a MOVBE-enabled 3.9-rc6+ kernel in kvm executes MOVBE ~60K times. Signed-off-by: Andre Przywara <andre@andrep.de> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-10-30kvm, emulator: Add initial three-byte insns supportBorislav Petkov1-0/+30
Add initial support for handling three-byte instructions in the emulator. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-10-30kvm, emulator: Rename VendorSpecific flagBorislav Petkov1-7/+7
Call it EmulateOnUD which is exactly what we're trying to do with vendor-specific instructions. Rename ->only_vendor_specific_insn to something shorter, while at it. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-10-30kvm, emulator: Use opcode lengthBorislav Petkov1-2/+3
Add a field to the current emulation context which contains the instruction opcode length. This will streamline handling of opcodes of different length. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-09-17KVM: x86 emulator: emulate RETF immBruce Rogers1-1/+13
Opcode CA This gets used by a DOS based NetWare guest. Signed-off-by: Bruce Rogers <brogers@suse.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-07-04Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-282/+109
Pull KVM fixes from Paolo Bonzini: "On the x86 side, there are some optimizations and documentation updates. The big ARM/KVM change for 3.11, support for AArch64, will come through Catalin Marinas's tree. s390 and PPC have misc cleanups and bugfixes" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (87 commits) KVM: PPC: Ignore PIR writes KVM: PPC: Book3S PR: Invalidate SLB entries properly KVM: PPC: Book3S PR: Allow guest to use 1TB segments KVM: PPC: Book3S PR: Don't keep scanning HPTEG after we find a match KVM: PPC: Book3S PR: Fix invalidation of SLB entry 0 on guest entry KVM: PPC: Book3S PR: Fix proto-VSID calculations KVM: PPC: Guard doorbell exception with CONFIG_PPC_DOORBELL KVM: Fix RTC interrupt coalescing tracking kvm: Add a tracepoint write_tsc_offset KVM: MMU: Inform users of mmio generation wraparound KVM: MMU: document fast invalidate all mmio sptes KVM: MMU: document fast invalidate all pages KVM: MMU: document fast page fault KVM: MMU: document mmio page fault KVM: MMU: document write_flooding_count KVM: MMU: document clear_spte_count KVM: MMU: drop kvm_mmu_zap_mmio_sptes KVM: MMU: init kvm generation close to mmio wrap-around value KVM: MMU: add tracepoint for check_mmio_spte KVM: MMU: fast invalidate all mmio sptes ...
2013-06-03KVM: fix sil/dil/bpl/spl in the mod/rm fieldsPaolo Bonzini1-1/+4
The x86-64 extended low-byte registers were fetched correctly from reg, but not from mod/rm. This fixes another bug in the boot of RHEL5.9 64-bit, but it is still not enough. Cc: <stable@vger.kernel.org> # 3.9 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-06-03KVM: Emulate multibyte NOPPaolo Bonzini1-1/+3
This is encountered when booting RHEL5.9 64-bit. There is another bug after this one that is not a simple emulation failure, but this one lets the boot proceed a bit. Cc: <stable@vger.kernel.org> # 3.9 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-21KVM: x86 emulator: convert XADD to fastopAvi Kivity1-7/+3
Signed-off-by: Avi Kivity <avi.kivity@gmail.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-21KVM: x86 emulator: drop unused old-style inline emulationAvi Kivity1-198/+0
Signed-off-by: Avi Kivity <avi.kivity@gmail.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-21KVM: x86 emulator: convert DIV/IDIV to fastopAvi Kivity1-25/+26
Since DIV and IDIV can generate exceptions, we need an additional output parameter indicating whether an execption has occured. To avoid increasing register pressure on i386, we use %rsi, which is already allocated for the fastop code pointer. Gleb: added comment about fop usage as exception indication. Signed-off-by: Avi Kivity <avi.kivity@gmail.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-21KVM: x86 emulator: convert single-operand MUL/IMUL to fastopAvi Kivity1-19/+16
Signed-off-by: Avi Kivity <avi.kivity@gmail.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-21KVM: x86 emulator: Switch fastop src operand to RDXAvi Kivity1-13/+13
This makes OpAccHi useful. Signed-off-by: Avi Kivity <avi.kivity@gmail.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-21KVM: x86 emulator: switch MUL/DIV to DstXaccAvi Kivity1-7/+8
Signed-off-by: Avi Kivity <avi.kivity@gmail.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-21KVM: x86 emulator: decode extended accumulator explicityAvi Kivity1-0/+24
Single-operand MUL and DIV access an extended accumulator: AX for byte instructions, and DX:AX, EDX:EAX, or RDX:RAX for larger-sized instructions. Add support for fetching the extended accumulator. In order not to change things too much, RDX is loaded into Src2, which is already loaded by fastop(). This avoids increasing register pressure on i386. Gleb: disable src writeback for ByteOp div/mul. Signed-off-by: Avi Kivity <avi.kivity@gmail.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-21KVM: x86 emulator: add support for writing back the source operandAvi Kivity1-21/+27
Some instructions write back the source operand, not just the destination. Add support for doing this via the decode flags. Gleb: add BUG_ON() to prevent source to be memory operand. Signed-off-by: Avi Kivity <avi.kivity@gmail.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-09KVM: emulator: emulate SALCPaolo Bonzini1-1/+5
This is an almost-undocumented instruction available in 32-bit mode. I say "almost" undocumented because AMD documents it in their opcode maps just to say that it is unavailable in 64-bit mode (sections "A.2.1 One-Byte Opcodes" and "B.3 Invalid and Reassigned Instructions in 64-Bit Mode"). It is roughly equivalent to "sbb %al, %al" except it does not set the flags. Use fastop to emulate it, but do not use the opcode directly because it would fail if the host is 64-bit! Reported-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: stable@vger.kernel.org # 3.9 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-09KVM: emulator: emulate XLATPaolo Bonzini1-1/+14
This is used by SGABIOS, KVM breaks with emulate_invalid_guest_state=1. It is just a MOV in disguise, with a funny source address. Reported-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: stable@vger.kernel.org # 3.9 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-09KVM: emulator: emulate AAMPaolo Bonzini1-1/+24
This is used by SGABIOS, KVM breaks with emulate_invalid_guest_state=1. AAM needs the source operand to be unsigned; do the same in AAD as well for consistency, even though it does not affect the result. Reported-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: stable@vger.kernel.org # 3.9 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-25KVM: X86 emulator: fix source operand decoding for 8bit mov[zs]x instructionsGleb Natapov1-0/+4
Source operand for one byte mov[zs]x is decoded incorrectly if it is in high byte register. Fix that. Cc: stable@vger.kernel.org Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-14KVM: emulator: mark 0xff 0x7d opcode as undefined.Gleb Natapov1-1/+1
Signed-off-by: Gleb Natapov <gleb@redhat.com>
generated by cgit v1.2.3 (git 2.39.0) at 2025-09-24 18:51:22 +0300