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KVM: handle exit due to INVD in VMX

PATCH Applied Gleb Natapov 2 participants 2 messages Nov 1, 2010

Subsystems (3)
x86 KVM KVM x86
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Gleb Natapov

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#0 lore raw

PATCH v2 1/1 KVM: handle exit due to INVD in VMX

Currently the exit is unhandled, so guest halts with error if it tries to execute INVD instruction. Call into emulator when INVD instruction is executed by a guest instead. This instruction is not needed by ordinary guests, but firmware (like OpenBIOS) use it and fail.

Signed-off-by Gleb Natapov <[email protected]>

---
ChangeLog:
v1->v2
- New and improved patch description

arch/x86/include/asm/vmx.h +1 -0
index 9f0cbd9..42d9590 100644
@@ -239,6 +239,7 @@ enum vmcs_field {
 #define EXIT_REASON_TASK_SWITCH         9
 #define EXIT_REASON_CPUID               10
 #define EXIT_REASON_HLT                 12
+#define EXIT_REASON_INVD                13
 #define EXIT_REASON_INVLPG              14
 #define EXIT_REASON_RDPMC               15
 #define EXIT_REASON_RDTSC               16
arch/x86/kvm/vmx.c +6 -0
index 993e332..200533e 100644
@@ -3350,6 +3350,11 @@ static int handle_vmx_insn(struct kvm_vcpu *vcpu)
 	return 1;
 }
 
+static int handle_invd(struct kvm_vcpu *vcpu)
+{
+	return emulate_instruction(vcpu, 0, 0, 0) == EMULATE_DONE;
+}
+
 static int handle_invlpg(struct kvm_vcpu *vcpu)
 {
 	unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION);

@@ -3650,6 +3655,7 @@ static int (*kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = {
 	[EXIT_REASON_MSR_WRITE]               = handle_wrmsr,
 	[EXIT_REASON_PENDING_INTERRUPT]       = handle_interrupt_window,
 	[EXIT_REASON_HLT]                     = handle_halt,
+	[EXIT_REASON_INVD]		      = handle_invd,
 	[EXIT_REASON_INVLPG]		      = handle_invlpg,
 	[EXIT_REASON_VMCALL]                  = handle_vmcall,
 	[EXIT_REASON_VMCLEAR]	              = handle_vmx_insn,

--
Gleb.

Applied
#1 lore raw
Quoted 10 lines · Gleb Natapov

Currently the exit is unhandled, so guest halts with error if it tries to execute INVD instruction. Call into emulator when INVD instruction is executed by a guest instead. This instruction is not needed by ordinary guests, but firmware (like OpenBIOS) use it and fail.

Signed-off-by Gleb Natapov <[email protected]>

---
ChangeLog:
v1->v2
- New and improved patch description

Applied, thanks.