From patchwork Wed Mar 14 22:18:41 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [Natty, 1/2] KVM: x86: extend "struct x86_emulate_ops" with "get_cpuid" From: Stefan Bader X-Patchwork-Id: 146741 Message-Id: <1331763526-32743-6-git-send-email-stefan.bader@canonical.com> To: kernel-team@lists.ubuntu.com Date: Wed, 14 Mar 2012 23:18:41 +0100 >From 4daadc97a978d903011c54c2caec5824f06a215d 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 5/6] 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 (backported from commit bdb42f5afebe208eae90406959383856ae2caf2b upstream) Signed-off-by: Stefan Bader --- arch/x86/include/asm/kvm_emulate.h | 3 +++ arch/x86/kvm/x86.c | 22 ++++++++++++++++++++++ 2 files changed, 25 insertions(+), 0 deletions(-) diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h index 8e37deb..ff22d58 100644 --- a/arch/x86/include/asm/kvm_emulate.h +++ b/arch/x86/include/asm/kvm_emulate.h @@ -158,6 +158,9 @@ struct x86_emulate_ops { int (*set_dr)(int dr, unsigned long value, struct kvm_vcpu *vcpu); int (*set_msr)(struct kvm_vcpu *vcpu, u32 msr_index, u64 data); int (*get_msr)(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata); + + bool (*get_cpuid)(struct kvm_vcpu *vcpu, + u32 *eax, u32 *ebx, u32 *ecx, u32 *edx); }; /* Type, address-of, and value of an instruction's operand. */ diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 0556e05..bc5d1d2 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4212,6 +4212,27 @@ static void emulator_set_segment_selector(u16 sel, int seg, kvm_set_segment(vcpu, &kvm_seg, seg); } +static bool emulator_get_cpuid(struct kvm_vcpu *vcpu, + u32 *eax, u32 *ebx, u32 *ecx, u32 *edx) +{ + struct kvm_cpuid_entry2 *cpuid = NULL; + + if (eax && ecx) + cpuid = kvm_find_cpuid_entry(vcpu, *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, @@ -4235,6 +4256,7 @@ static struct x86_emulate_ops emulate_ops = { .set_dr = emulator_set_dr, .set_msr = kvm_set_msr, .get_msr = kvm_get_msr, + .get_cpuid = emulator_get_cpuid, }; static void cache_all_regs(struct kvm_vcpu *vcpu)