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From: Maxim Levitsky <mlevitsk@redhat.com>
To: kvm@vger.kernel.org
Cc: Ingo Molnar <mingo@redhat.com>,
	linux-kernel@vger.kernel.org (open list:X86 ARCHITECTURE (32-BIT
	AND 64-BIT)), Jim Mattson <jmattson@google.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
	Joerg Roedel <joro@8bytes.org>, Borislav Petkov <bp@alien8.de>,
	Thomas Gleixner <tglx@linutronix.de>,
	Wanpeng Li <wanpengli@tencent.com>,
	Sean Christopherson <seanjc@google.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Maxim Levitsky <mlevitsk@redhat.com>
Subject: [PATCH 1/4] KVM: x86: determine if an exception has an error code only when injecting it.
Date: Thu, 25 Feb 2021 17:41:32 +0200	[thread overview]
Message-ID: <20210225154135.405125-2-mlevitsk@redhat.com> (raw)
In-Reply-To: <20210225154135.405125-1-mlevitsk@redhat.com>

A page fault can be queued while vCPU is in real paged mode on AMD, and
AMD manual asks the user to always intercept it
(otherwise result is undefined).
The resulting VM exit, does have an error code.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
---
 arch/x86/kvm/x86.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9fa0c7ff6e2fb..a9d814a0b5e4f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -544,8 +544,6 @@ static void kvm_multiple_exception(struct kvm_vcpu *vcpu,
 
 	if (!vcpu->arch.exception.pending && !vcpu->arch.exception.injected) {
 	queue:
-		if (has_error && !is_protmode(vcpu))
-			has_error = false;
 		if (reinject) {
 			/*
 			 * On vmentry, vcpu->arch.exception.pending is only
@@ -8345,6 +8343,13 @@ static void update_cr8_intercept(struct kvm_vcpu *vcpu)
 	static_call(kvm_x86_update_cr8_intercept)(vcpu, tpr, max_irr);
 }
 
+static void kvm_inject_exception(struct kvm_vcpu *vcpu)
+{
+	if (vcpu->arch.exception.error_code && !is_protmode(vcpu))
+		vcpu->arch.exception.error_code = false;
+	static_call(kvm_x86_queue_exception)(vcpu);
+}
+
 static void inject_pending_event(struct kvm_vcpu *vcpu, bool *req_immediate_exit)
 {
 	int r;
@@ -8353,7 +8358,7 @@ static void inject_pending_event(struct kvm_vcpu *vcpu, bool *req_immediate_exit
 	/* try to reinject previous events if any */
 
 	if (vcpu->arch.exception.injected) {
-		static_call(kvm_x86_queue_exception)(vcpu);
+		kvm_inject_exception(vcpu);
 		can_inject = false;
 	}
 	/*
@@ -8416,7 +8421,7 @@ static void inject_pending_event(struct kvm_vcpu *vcpu, bool *req_immediate_exit
 			}
 		}
 
-		static_call(kvm_x86_queue_exception)(vcpu);
+		kvm_inject_exception(vcpu);
 		can_inject = false;
 	}
 
-- 
2.26.2


  reply	other threads:[~2021-02-25 15:43 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-25 15:41 [PATCH 0/4] RFC/WIP: KVM: separate injected and pending exception + few more fixes Maxim Levitsky
2021-02-25 15:41 ` Maxim Levitsky [this message]
2021-02-25 15:41 ` [PATCH 2/4] KVM: x86: mmu: initialize fault.async_page_fault in walk_addr_generic Maxim Levitsky
2021-02-25 15:41 ` [PATCH 3/4] KVM: x86: pending exception must be be injected even with an injected event Maxim Levitsky
2021-02-25 16:05   ` Paolo Bonzini
2021-02-25 16:06     ` Maxim Levitsky
2021-02-25 17:25       ` Paolo Bonzini
2021-02-25 15:41 ` [PATCH 4/4] kvm: WIP separation of injected and pending exception Maxim Levitsky
2021-02-25 15:48 ` [PATCH 0/4] RFC/WIP: KVM: separate injected and pending exception + few more fixes Maxim Levitsky

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