[PATCH 0/4] Add rudimentary Hyper-V guest support v3

[PATCH 0/4] Add rudimentary Hyper-V guest support v3

[Alexander Graf]

Now that we have nested SVM in place, let's make use of it and virtualize
something non-kvm.
The first interesting target that came to my mind here was Hyper-V.

This patchset makes Windows Server 2008 boot with Hyper-V, which runs
the "dom0" in virtualized mode already. It hangs somewhere in IDE code when
booted, so I haven't been able to run a second VM within for now yet.

Please keep in mind that Hyper-V won't work unless you apply the userspace
patches too and the PAT bit patch

---

v2 changes:
  - remove reserved PAT check patch (Avi will do this)
  - remove #PF inject on emulated_read
  - take comments from v1 into account (listed individually)

v3 changes:
  - forward-port to current git

Alexander Graf (4):
  Add definition for IGNNE MSR
  Implement Hyper-V MSRs v2
  Nested SVM: Implement INVLPGA v2
  Nested SVM: Improve interrupt injection v2

 arch/x86/include/asm/msr-index.h |    1 +
 arch/x86/kvm/svm.c               |   59 +++++++++++++++++++++++++++----------
 2 files changed, 44 insertions(+), 16 deletions(-)

[PATCH 1/4] Add definition for IGNNE MSR

[Alexander Graf]

Hyper-V tried to access MSR_IGNNE, so let's at least have a definition
for it in our headers.

Signed-off-by: Alexander Graf <agraf@suse.de>
---
 arch/x86/include/asm/msr-index.h |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index ec41fc1..e273549 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -372,6 +372,7 @@
 /* AMD-V MSRs */
 
 #define MSR_VM_CR                       0xc0010114
+#define MSR_VM_IGNNE                    0xc0010115
 #define MSR_VM_HSAVE_PA                 0xc0010117
 
 #endif /* _ASM_X86_MSR_INDEX_H */
-- 
1.6.0.2

[PATCH 2/4] Implement Hyper-V MSRs

[Alexander Graf]

Hyper-V uses some MSRs, some of which are actually reserved for BIOS usage.

But let's be nice today and have it its way, because otherwise it fails
terribly.

v2 changes:
  - remove the 0x40000081 MSR definition
  - add pr_unimpl() on unimplemented writes

Signed-off-by: Alexander Graf <agraf@suse.de>
---
 arch/x86/kvm/svm.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index ef43a18..4b4eadd 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2034,6 +2034,11 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, unsigned ecx, u64 data)
 	case MSR_VM_HSAVE_PA:
 		svm->hsave_msr = data;
 		break;
+	case MSR_VM_CR:
+	case MSR_VM_IGNNE:
+	case MSR_K8_HWCR:
+		pr_unimpl(vcpu, "unimplemented wrmsr: 0x%x data 0x%llx\n", ecx, data);
+		break;
 	default:
 		return kvm_set_msr_common(vcpu, ecx, data);
 	}
-- 
1.6.0.2

[PATCH 3/4] Nested SVM: Implement INVLPGA

[Alexander Graf]

SVM adds another way to do INVLPG by ASID which Hyper-V makes use of,
so let's implement it!

For now we just do the same thing invlpg does, as asid switching
means we flush the mmu anyways. That might change one day though.

v2 makes invlpga do the same as invlpg, not flush the whole mmu

Signed-off-by: Alexander Graf <agraf@suse.de>
---
 arch/x86/kvm/svm.c |   15 ++++++++++++++-
 1 files changed, 14 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 4b4eadd..fa2a710 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1785,6 +1785,19 @@ static int clgi_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
 	return 1;
 }
 
+static int invlpga_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
+{
+	struct kvm_vcpu *vcpu = &svm->vcpu;
+	nsvm_printk("INVLPGA\n");
+
+	/* Let's treat INVLPGA the same as INVLPG (can be optimized!) */
+	kvm_mmu_invlpg(vcpu, vcpu->arch.regs[VCPU_REGS_RAX]);
+
+	svm->next_rip = kvm_rip_read(&svm->vcpu) + 3;
+	skip_emulated_instruction(&svm->vcpu);
+	return 1;
+}
+
 static int invalid_op_interception(struct vcpu_svm *svm,
 				   struct kvm_run *kvm_run)
 {
@@ -2130,7 +2143,7 @@ static int (*svm_exit_handlers[])(struct vcpu_svm *svm,
 	[SVM_EXIT_INVD]                         = emulate_on_interception,
 	[SVM_EXIT_HLT]				= halt_interception,
 	[SVM_EXIT_INVLPG]			= invlpg_interception,
-	[SVM_EXIT_INVLPGA]			= invalid_op_interception,
+	[SVM_EXIT_INVLPGA]			= invlpga_interception,
 	[SVM_EXIT_IOIO] 		  	= io_interception,
 	[SVM_EXIT_MSR]				= msr_interception,
 	[SVM_EXIT_TASK_SWITCH]			= task_switch_interception,
-- 
1.6.0.2

[PATCH 4/4] Nested SVM: Improve interrupt injection

[Alexander Graf]

While trying to get Hyper-V running, I realized that the interrupt injection
mechanisms that are in place right now are not 100% correct.

This patch makes nested SVM's interrupt injection behave more like on a
real machine.

v2 calls BUG_ON when svm_set_irq is called with GIF=0

Signed-off-by: Alexander Graf <agraf@suse.de>
---
 arch/x86/kvm/svm.c |   39 ++++++++++++++++++++++++---------------
 1 files changed, 24 insertions(+), 15 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index fa2a710..5b14c9d 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1517,7 +1517,8 @@ static int nested_svm_vmexit_real(struct vcpu_svm *svm, void *arg1,
 	/* Kill any pending exceptions */
 	if (svm->vcpu.arch.exception.pending == true)
 		nsvm_printk("WARNING: Pending Exception\n");
-	svm->vcpu.arch.exception.pending = false;
+	kvm_clear_exception_queue(&svm->vcpu);
+	kvm_clear_interrupt_queue(&svm->vcpu);
 
 	/* Restore selected save entries */
 	svm->vmcb->save.es = hsave->save.es;
@@ -1585,7 +1586,8 @@ static int nested_svm_vmrun(struct vcpu_svm *svm, void *arg1,
 	svm->nested_vmcb = svm->vmcb->save.rax;
 
 	/* Clear internal status */
-	svm->vcpu.arch.exception.pending = false;
+	kvm_clear_exception_queue(&svm->vcpu);
+	kvm_clear_interrupt_queue(&svm->vcpu);
 
 	/* Save the old vmcb, so we don't need to pick what we save, but
 	   can restore everything when a VMEXIT occurs */
@@ -2277,21 +2279,14 @@ static inline void svm_inject_irq(struct vcpu_svm *svm, int irq)
 		((/*control->int_vector >> 4*/ 0xf) << V_INTR_PRIO_SHIFT);
 }
 
-static void svm_queue_irq(struct kvm_vcpu *vcpu, unsigned nr)
-{
-	struct vcpu_svm *svm = to_svm(vcpu);
-
-	svm->vmcb->control.event_inj = nr |
-		SVM_EVTINJ_VALID | SVM_EVTINJ_TYPE_INTR;
-}
-
 static void svm_set_irq(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
 
-	nested_svm_intr(svm);
+	BUG_ON(!(svm->vcpu.arch.hflags & HF_GIF_MASK));
 
-	svm_queue_irq(vcpu, vcpu->arch.interrupt.nr);
+	svm->vmcb->control.event_inj = vcpu->arch.interrupt.nr |
+		SVM_EVTINJ_VALID | SVM_EVTINJ_TYPE_INTR;
 }
 
 static void update_cr8_intercept(struct kvm_vcpu *vcpu, int tpr, int irr)
@@ -2319,13 +2314,25 @@ static int svm_interrupt_allowed(struct kvm_vcpu *vcpu)
 	struct vmcb *vmcb = svm->vmcb;
 	return (vmcb->save.rflags & X86_EFLAGS_IF) &&
 		!(vmcb->control.int_state & SVM_INTERRUPT_SHADOW_MASK) &&
-		(svm->vcpu.arch.hflags & HF_GIF_MASK);
+		(svm->vcpu.arch.hflags & HF_GIF_MASK) &&
+		!is_nested(svm);
 }
 
 static void enable_irq_window(struct kvm_vcpu *vcpu)
 {
-	svm_set_vintr(to_svm(vcpu));
-	svm_inject_irq(to_svm(vcpu), 0x0);
+	struct vcpu_svm *svm = to_svm(vcpu);
+	nsvm_printk("Trying to open IRQ window\n");
+
+	nested_svm_intr(svm);
+
+	/* In case GIF=0 we can't rely on the CPU to tell us when
+	 * GIF becomes 1, because that's a separate STGI/VMRUN intercept.
+	 * The next time we get that intercept, this function will be
+	 * called again though and we'll get the vintr intercept. */
+	if (svm->vcpu.arch.hflags & HF_GIF_MASK) {
+		svm_set_vintr(svm);
+		svm_inject_irq(svm, 0x0);
+	}
 }
 
 static void enable_nmi_window(struct kvm_vcpu *vcpu)
@@ -2393,6 +2400,8 @@ static void svm_complete_interrupts(struct vcpu_svm *svm)
 	case SVM_EXITINTINFO_TYPE_EXEPT:
 		/* In case of software exception do not reinject an exception
 		   vector, but re-execute and instruction instead */
+		if (is_nested(svm))
+			break;
 		if (kvm_exception_is_soft(vector))
 			break;
 		if (exitintinfo & SVM_EXITINTINFO_VALID_ERR) {
-- 
1.6.0.2

Re: [PATCH 0/4] Add rudimentary Hyper-V guest support v3

[Avi Kivity]

On 06/15/2009 04:21 PM, Alexander Graf wrote:
> Now that we have nested SVM in place, let's make use of it and virtualize
> something non-kvm.
> The first interesting target that came to my mind here was Hyper-V.
>
> This patchset makes Windows Server 2008 boot with Hyper-V, which runs
> the "dom0" in virtualized mode already. It hangs somewhere in IDE code when
> booted, so I haven't been able to run a second VM within for now yet.
>
>    

Applied all, thanks.

> Please keep in mind that Hyper-V won't work unless you apply the userspace
> patches too

Please rebase/repost those.

> and the PAT bit patch
>    

That's fd2e987d5 unless I'm confusing this with another issue.

-- 
error compiling committee.c: too many arguments to function