[ 087/149] KVM: x86: extend "struct x86_emulate_ops" with "get_cpuid"

From: Greg KH
Date: Fri Mar 30 2012 - 18:17:38 EST


3.2-stable review patch. If anyone has any objections, please let me know.

------------------

From: =?UTF-8?q?Stephan=20B=C3=A4rwolf?= <stephan.baerwolf@xxxxxxxxxxxxx>

commit bdb42f5afebe208eae90406959383856ae2caf2b upstream.

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 <stephan.baerwolf@xxxxxxxxxxxxx>
Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
Signed-off-by: Stefan Bader <stefan.bader@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/x86/include/asm/kvm_emulate.h | 3 +++
arch/x86/kvm/x86.c | 23 +++++++++++++++++++++++
2 files changed, 26 insertions(+)

--- 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;
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4655,6 +4655,28 @@ static int emulator_intercept(struct x86
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,
@@ -4685,6 +4707,7 @@ static struct x86_emulate_ops emulate_op
.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)


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