From patchwork Wed Mar 14 22:18:43 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [Oneiric, 1/2] KVM: x86: extend "struct x86_emulate_ops" with "get_cpuid" From: Stefan Bader X-Patchwork-Id: 146748 Message-Id: <1331763526-32743-8-git-send-email-stefan.bader@canonical.com> To: kernel-team@lists.ubuntu.com Date: Wed, 14 Mar 2012 23:18:43 +0100 >From eaee58e1433e1b16e686cfcdcbc207d4310a239f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Stephan=20B=C3=A4rwolf?= Date: Thu, 12 Jan 2012 16:43:03 +0100 Subject: [PATCH 7/8] KVM: x86: extend "struct x86_emulate_ops" with "get_cpuid" In order to be able to proceed checks on CPU-specific properties within the emulator, function "get_cpuid" is introduced. With "get_cpuid" it is possible to virtually call the guests "cpuid"-opcode without changing the VM's context. [mtosatti: cleanup/beautify code] Signed-off-by: Stephan Baerwolf Signed-off-by: Marcelo Tosatti CVE-2012-0045 BugLink: http://bugs.launchpad.net/bugs/917842 (cherry-picked from commit bdb42f5afebe208eae90406959383856ae2caf2b upstream) Signed-off-by: Stefan Bader --- arch/x86/include/asm/kvm_emulate.h | 3 +++ arch/x86/kvm/x86.c | 23 +++++++++++++++++++++++ 2 files changed, 26 insertions(+), 0 deletions(-) diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h index 0049211..18e54f1 100644 --- a/arch/x86/include/asm/kvm_emulate.h +++ b/arch/x86/include/asm/kvm_emulate.h @@ -189,6 +189,9 @@ struct x86_emulate_ops { int (*intercept)(struct x86_emulate_ctxt *ctxt, struct x86_instruction_info *info, enum x86_intercept_stage stage); + + bool (*get_cpuid)(struct x86_emulate_ctxt *ctxt, + u32 *eax, u32 *ebx, u32 *ecx, u32 *edx); }; typedef u32 __attribute__((vector_size(16))) sse128_t; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index bc58ede..8e15578 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4436,6 +4436,28 @@ static int emulator_intercept(struct x86_emulate_ctxt *ctxt, return kvm_x86_ops->check_intercept(emul_to_vcpu(ctxt), info, stage); } +static bool emulator_get_cpuid(struct x86_emulate_ctxt *ctxt, + u32 *eax, u32 *ebx, u32 *ecx, u32 *edx) +{ + struct kvm_cpuid_entry2 *cpuid = NULL; + + if (eax && ecx) + cpuid = kvm_find_cpuid_entry(emul_to_vcpu(ctxt), + *eax, *ecx); + + if (cpuid) { + *eax = cpuid->eax; + *ecx = cpuid->ecx; + if (ebx) + *ebx = cpuid->ebx; + if (edx) + *edx = cpuid->edx; + return true; + } + + return false; +} + static struct x86_emulate_ops emulate_ops = { .read_std = kvm_read_guest_virt_system, .write_std = kvm_write_guest_virt_system, @@ -4466,6 +4488,7 @@ static struct x86_emulate_ops emulate_ops = { .get_fpu = emulator_get_fpu, .put_fpu = emulator_put_fpu, .intercept = emulator_intercept, + .get_cpuid = emulator_get_cpuid, }; static void cache_all_regs(struct kvm_vcpu *vcpu)