Right now, the VMX preemption timer is special cased via the hv_timer_pending, but the purpose of the callback can be easily extended to observing any event that can occur only in non-root mode. Interrupts, NMIs etc. are already handled properly by the *_interrupt_allowed callbacks, so what is missing is only MTF. Check it in the newly-renamed callback, so that kvm_vcpu_running's call to kvm_check_nested_events becomes redundant.
Cc: stable@vger.kernel.org Reported-by: Maxim Levitsky mlevitsk@redhat.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com --- arch/x86/include/asm/kvm_host.h | 2 +- arch/x86/kvm/vmx/nested.c | 7 ++++++- arch/x86/kvm/x86.c | 8 ++++---- 3 files changed, 11 insertions(+), 6 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 4ff36610af6a..e2e4f60159e9 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1504,7 +1504,7 @@ struct kvm_x86_ops { struct kvm_x86_nested_ops { void (*leave_nested)(struct kvm_vcpu *vcpu); int (*check_events)(struct kvm_vcpu *vcpu); - bool (*hv_timer_pending)(struct kvm_vcpu *vcpu); + bool (*has_events)(struct kvm_vcpu *vcpu); void (*triple_fault)(struct kvm_vcpu *vcpu); int (*get_state)(struct kvm_vcpu *vcpu, struct kvm_nested_state __user *user_kvm_nested_state, diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 856c87563883..54672025c3a1 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -3857,6 +3857,11 @@ static bool nested_vmx_preemption_timer_pending(struct kvm_vcpu *vcpu) to_vmx(vcpu)->nested.preemption_timer_expired; }
+static bool vmx_has_nested_events(struct kvm_vcpu *vcpu) +{ + return nested_vmx_preemption_timer_pending(vcpu) || vmx->nested.mtf_pending; +} + static int vmx_check_nested_events(struct kvm_vcpu *vcpu) { struct vcpu_vmx *vmx = to_vmx(vcpu); @@ -6809,7 +6814,7 @@ __init int nested_vmx_hardware_setup(int (*exit_handlers[])(struct kvm_vcpu *)) struct kvm_x86_nested_ops vmx_nested_ops = { .leave_nested = vmx_leave_nested, .check_events = vmx_check_nested_events, - .hv_timer_pending = nested_vmx_preemption_timer_pending, + .has_events = vmx_has_nested_events, .triple_fault = nested_vmx_triple_fault, .get_state = vmx_get_nested_state, .set_state = vmx_set_nested_state, diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index a6ab19afc638..0e73607b02bd 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9471,8 +9471,8 @@ static int inject_pending_event(struct kvm_vcpu *vcpu, bool *req_immediate_exit) }
if (is_guest_mode(vcpu) && - kvm_x86_ops.nested_ops->hv_timer_pending && - kvm_x86_ops.nested_ops->hv_timer_pending(vcpu)) + kvm_x86_ops.nested_ops->has_events && + kvm_x86_ops.nested_ops->has_events(vcpu)) *req_immediate_exit = true;
WARN_ON(vcpu->arch.exception.pending); @@ -12183,8 +12183,8 @@ static inline bool kvm_vcpu_has_events(struct kvm_vcpu *vcpu) return true;
if (is_guest_mode(vcpu) && - kvm_x86_ops.nested_ops->hv_timer_pending && - kvm_x86_ops.nested_ops->hv_timer_pending(vcpu)) + kvm_x86_ops.nested_ops->has_events && + kvm_x86_ops.nested_ops->has_events(vcpu)) return true;
return false;
On Wed, 2022-04-27 at 13:37 -0400, Paolo Bonzini wrote:
Right now, the VMX preemption timer is special cased via the hv_timer_pending, but the purpose of the callback can be easily extended to observing any event that can occur only in non-root mode. Interrupts, NMIs etc. are already handled properly by the *_interrupt_allowed callbacks, so what is missing is only MTF. Check it in the newly-renamed callback, so that kvm_vcpu_running's call to kvm_check_nested_events becomes redundant.
Cc: stable@vger.kernel.org Reported-by: Maxim Levitsky mlevitsk@redhat.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com
arch/x86/include/asm/kvm_host.h | 2 +- arch/x86/kvm/vmx/nested.c | 7 ++++++- arch/x86/kvm/x86.c | 8 ++++---- 3 files changed, 11 insertions(+), 6 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 4ff36610af6a..e2e4f60159e9 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1504,7 +1504,7 @@ struct kvm_x86_ops { struct kvm_x86_nested_ops { void (*leave_nested)(struct kvm_vcpu *vcpu); int (*check_events)(struct kvm_vcpu *vcpu);
- bool (*hv_timer_pending)(struct kvm_vcpu *vcpu);
- bool (*has_events)(struct kvm_vcpu *vcpu); void (*triple_fault)(struct kvm_vcpu *vcpu); int (*get_state)(struct kvm_vcpu *vcpu, struct kvm_nested_state __user *user_kvm_nested_state,
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 856c87563883..54672025c3a1 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -3857,6 +3857,11 @@ static bool nested_vmx_preemption_timer_pending(struct kvm_vcpu *vcpu) to_vmx(vcpu)->nested.preemption_timer_expired; } +static bool vmx_has_nested_events(struct kvm_vcpu *vcpu) +{
Typo: needs struct vcpu_vmx *vmx = to_vmx(vcpu);
- return nested_vmx_preemption_timer_pending(vcpu) || vmx->nested.mtf_pending;
+}
static int vmx_check_nested_events(struct kvm_vcpu *vcpu) { struct vcpu_vmx *vmx = to_vmx(vcpu); @@ -6809,7 +6814,7 @@ __init int nested_vmx_hardware_setup(int (*exit_handlers[])(struct kvm_vcpu *)) struct kvm_x86_nested_ops vmx_nested_ops = { .leave_nested = vmx_leave_nested, .check_events = vmx_check_nested_events,
- .hv_timer_pending = nested_vmx_preemption_timer_pending,
- .has_events = vmx_has_nested_events, .triple_fault = nested_vmx_triple_fault, .get_state = vmx_get_nested_state, .set_state = vmx_set_nested_state,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index a6ab19afc638..0e73607b02bd 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9471,8 +9471,8 @@ static int inject_pending_event(struct kvm_vcpu *vcpu, bool *req_immediate_exit) } if (is_guest_mode(vcpu) &&
kvm_x86_ops.nested_ops->hv_timer_pending &&kvm_x86_ops.nested_ops->hv_timer_pending(vcpu))
kvm_x86_ops.nested_ops->has_events &&kvm_x86_ops.nested_ops->has_events(vcpu))WARN_ON(vcpu->arch.exception.pending); @@ -12183,8 +12183,8 @@ static inline bool kvm_vcpu_has_events(struct kvm_vcpu *vcpu) return true; if (is_guest_mode(vcpu) &&
kvm_x86_ops.nested_ops->hv_timer_pending &&kvm_x86_ops.nested_ops->hv_timer_pending(vcpu))
kvm_x86_ops.nested_ops->has_events &&kvm_x86_ops.nested_ops->has_events(vcpu))
Nitpick: Won't it make sense to use conditional static call here instead?
return true;return false;
Besides nitpicks,
Reviewed-by: Maxim Levitsky mlevitsk@redhat.com
Wasn't able to test on my intel laptop, I am getting out of sudden in qemu:
'cpuid_data is full, no space for cpuid(eax:0x8000001d,ecx:0x3e)'
I will investigate tomorrow.
Best regards, Maxim Levitsky
On Wed, Apr 27, 2022, Paolo Bonzini wrote:
Right now, the VMX preemption timer is special cased via the hv_timer_pending, but the purpose of the callback can be easily extended to observing any event that can occur only in non-root mode. Interrupts, NMIs etc. are already handled properly by the *_interrupt_allowed callbacks, so what is missing is only MTF. Check it in the newly-renamed callback, so that kvm_vcpu_running's call to kvm_check_nested_events becomes redundant.
Cc: stable@vger.kernel.org Reported-by: Maxim Levitsky mlevitsk@redhat.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com
arch/x86/include/asm/kvm_host.h | 2 +- arch/x86/kvm/vmx/nested.c | 7 ++++++- arch/x86/kvm/x86.c | 8 ++++---- 3 files changed, 11 insertions(+), 6 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 4ff36610af6a..e2e4f60159e9 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1504,7 +1504,7 @@ struct kvm_x86_ops { struct kvm_x86_nested_ops { void (*leave_nested)(struct kvm_vcpu *vcpu); int (*check_events)(struct kvm_vcpu *vcpu);
- bool (*hv_timer_pending)(struct kvm_vcpu *vcpu);
- bool (*has_events)(struct kvm_vcpu *vcpu); void (*triple_fault)(struct kvm_vcpu *vcpu); int (*get_state)(struct kvm_vcpu *vcpu, struct kvm_nested_state __user *user_kvm_nested_state,
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 856c87563883..54672025c3a1 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -3857,6 +3857,11 @@ static bool nested_vmx_preemption_timer_pending(struct kvm_vcpu *vcpu) to_vmx(vcpu)->nested.preemption_timer_expired; } +static bool vmx_has_nested_events(struct kvm_vcpu *vcpu) +{
- return nested_vmx_preemption_timer_pending(vcpu) || vmx->nested.mtf_pending;
This doesn't even compile...
arch/x86/kvm/vmx/nested.c: In function ‘vmx_has_nested_events’: arch/x86/kvm/vmx/nested.c:3862:61: error: ‘vmx’ undeclared (first use in this function) 3862 | return nested_vmx_preemption_timer_pending(vcpu) || vmx->nested.mtf_pending; | ^~~ arch/x86/kvm/vmx/nested.c:3862:61: note: each undeclared identifier is reported only once for each function it appears in CC [M] arch/x86/kvm/svm/svm_onhyperv.o arch/x86/kvm/vmx/nested.c:3863:1: error: control reaches end of non-void function [-Werror=return-type] 3863 | } | ^ cc1: all warnings being treated as errors LD [M] arch/x86/kvm/kvm.o
On 4/29/22 19:03, Sean Christopherson wrote:
This doesn't even compile...
arch/x86/kvm/vmx/nested.c: In function ‘vmx_has_nested_events’: arch/x86/kvm/vmx/nested.c:3862:61: error: ‘vmx’ undeclared (first use in this function) 3862 | return nested_vmx_preemption_timer_pending(vcpu) || vmx->nested.mtf_pending; | ^~~ arch/x86/kvm/vmx/nested.c:3862:61: note: each undeclared identifier is reported only once for each function it appears in CC [M] arch/x86/kvm/svm/svm_onhyperv.o arch/x86/kvm/vmx/nested.c:3863:1: error: control reaches end of non-void function [-Werror=return-type] 3863 | } | ^ cc1: all warnings being treated as errors LD [M] arch/x86/kvm/kvm.o
Yeah, it doesn't. Of course this will need a v2, also because there are failures in the vmx tests.
What can I say, testing these patches on AMD hardware wasn't a great idea.
Paolo
On Fri, Apr 29, 2022, Paolo Bonzini wrote:
On 4/29/22 19:03, Sean Christopherson wrote:
This doesn't even compile...
arch/x86/kvm/vmx/nested.c: In function ‘vmx_has_nested_events’: arch/x86/kvm/vmx/nested.c:3862:61: error: ‘vmx’ undeclared (first use in this function) 3862 | return nested_vmx_preemption_timer_pending(vcpu) || vmx->nested.mtf_pending; | ^~~ arch/x86/kvm/vmx/nested.c:3862:61: note: each undeclared identifier is reported only once for each function it appears in CC [M] arch/x86/kvm/svm/svm_onhyperv.o arch/x86/kvm/vmx/nested.c:3863:1: error: control reaches end of non-void function [-Werror=return-type] 3863 | } | ^ cc1: all warnings being treated as errors LD [M] arch/x86/kvm/kvm.o
Yeah, it doesn't. Of course this will need a v2, also because there are failures in the vmx tests.
Heh, I suspected there would be failures, I was about to type up a response to patch 3. MTF is subtly relying on the call from kvm_vcpu_running() to inject the event.
From: Sean Christopherson seanjc@google.com Date: Fri, 29 Apr 2022 17:30:54 +0000 Subject: [PATCH] KVM: nVMX: Make an event request when pending an MTF nested VM-Exit
Set KVM_REQ_EVENT when MTF becomes pending to ensure that KVM will run through inject_pending_event() and thus vmx_check_nested_events() prior to re-entering the guest. MTF currently works by virtue of KVM's hack that calls kvm_check_nested_events() from kvm_vcpu_running(), but that hack will be removed in the near future.
Fixes: 5ef8acbdd687 ("KVM: nVMX: Emulate MTF when performing instruction emulation") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson seanjc@google.com --- arch/x86/kvm/vmx/vmx.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index d58b763df855..4c635bc08105 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -1577,10 +1577,12 @@ static void vmx_update_emulated_instruction(struct kvm_vcpu *vcpu) */ if (nested_cpu_has_mtf(vmcs12) && (!vcpu->arch.exception.pending || - vcpu->arch.exception.nr == DB_VECTOR)) + vcpu->arch.exception.nr == DB_VECTOR)) { vmx->nested.mtf_pending = true; - else + kvm_make_request(KVM_REQ_EVENT, vcpu); + } else { vmx->nested.mtf_pending = false; + } }
static int vmx_skip_emulated_instruction(struct kvm_vcpu *vcpu)
base-commit: 39aa5903e8c407e5128c15aeabb0717b275b007e --
linux-stable-mirror@lists.linaro.org
-
Maxim Levitsky -
Paolo Bonzini -
Sean Christopherson