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From: Jim Mattson <jmattson@google.com>
To: kvm@vger.kernel.org, pbonzini@redhat.com
Cc: Jim Mattson <jmattson@google.com>
Subject: [PATCH 06/12] KVM: nVMX: Fail on MMIO completion for nested posted interrupts
Date: Thu, 20 May 2021 16:03:33 -0700	[thread overview]
Message-ID: <20210520230339.267445-7-jmattson@google.com> (raw)
In-Reply-To: <20210520230339.267445-1-jmattson@google.com>

When the kernel has no mapping for the vmcs02 virtual APIC page,
userspace MMIO completion is necessary to process nested posted
interrupts. This is not a configuration that KVM supports. Rather than
silently ignoring the problem, try to exit to userspace with
KVM_INTERNAL_ERROR.

Note that the event that triggers this error is consumed as a
side-effect of a call to kvm_check_nested_events. On some paths
(notably through kvm_vcpu_check_block), the error is dropped. In any
case, this is an incremental improvement over always ignoring the
error.

Signed-off-by: Jim Mattson <jmattson@google.com>
---
 arch/x86/kvm/vmx/nested.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 7646e6e561ad..706c31821362 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -3700,7 +3700,7 @@ static int vmx_complete_nested_posted_interrupt(struct kvm_vcpu *vcpu)
 	if (max_irr != 256) {
 		vapic_page = vmx->nested.virtual_apic_map.hva;
 		if (!vapic_page)
-			return 0;
+			goto mmio_needed;
 
 		__kvm_apic_update_irr(vmx->nested.pi_desc->pir,
 			vapic_page, &max_irr);
@@ -3714,6 +3714,10 @@ static int vmx_complete_nested_posted_interrupt(struct kvm_vcpu *vcpu)
 
 	nested_mark_vmcs12_pages_dirty(vcpu);
 	return 0;
+
+mmio_needed:
+	kvm_handle_memory_failure(vcpu, X86EMUL_IO_NEEDED, NULL);
+	return -ENXIO;
 }
 
 static void nested_vmx_inject_exception_vmexit(struct kvm_vcpu *vcpu,
-- 
2.31.1.818.g46aad6cb9e-goog


  parent reply	other threads:[~2021-05-20 23:04 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-20 23:03 [PATCH 00/12] KVM: nVMX: Fix vmcs02 PID use-after-free issue Jim Mattson
2021-05-20 23:03 ` [PATCH 01/12] KVM: x86: Remove guest mode check from kvm_check_nested_events Jim Mattson
2021-05-20 23:03 ` [PATCH 02/12] KVM: x86: Wake up a vCPU when kvm_check_nested_events fails Jim Mattson
2021-05-24 15:43   ` Paolo Bonzini
2021-05-24 16:39     ` Jim Mattson
2021-05-24 16:43       ` Paolo Bonzini
2021-05-24 17:10         ` Jim Mattson
2021-05-24 23:10         ` Sean Christopherson
2021-05-24 23:23           ` Jim Mattson
2021-05-24 23:24             ` Sean Christopherson
2021-05-24 23:29               ` Jim Mattson
2021-05-24 23:34                 ` Sean Christopherson
2021-05-20 23:03 ` [PATCH 03/12] KVM: nVMX: Add a return code to vmx_complete_nested_posted_interrupt Jim Mattson
2021-05-20 23:03 ` [PATCH 04/12] KVM: x86: Add a return code to inject_pending_event Jim Mattson
2021-05-20 23:03 ` [PATCH 05/12] KVM: x86: Add a return code to kvm_apic_accept_events Jim Mattson
2021-05-25 19:24   ` Reiji Watanabe
2021-05-25 20:35     ` Jim Mattson
2021-05-20 23:03 ` Jim Mattson [this message]
2021-05-20 23:03 ` [PATCH 07/12] KVM: nVMX: Disable vmcs02 posted interrupts if vmcs12 PID isn't mappable Jim Mattson
2021-05-24 23:21   ` Sean Christopherson
2021-05-24 23:27     ` Jim Mattson
2021-05-24 23:45       ` Sean Christopherson
2021-05-25  0:03         ` Jim Mattson
2021-05-25  0:11           ` Sean Christopherson
2021-05-25  0:15             ` Jim Mattson
2021-05-25  0:57               ` Sean Christopherson
2021-05-20 23:03 ` [PATCH 08/12] KVM: selftests: Move APIC definitions into a separate file Jim Mattson
2021-05-20 23:03 ` [PATCH 09/12] KVM: selftests: Hoist APIC functions out of individual tests Jim Mattson
2021-05-20 23:03 ` [PATCH 10/12] KVM: selftests: Introduce x2APIC register manipulation functions Jim Mattson
2021-05-20 23:03 ` [PATCH 11/12] KVM: selftests: Introduce prepare_tpr_shadow Jim Mattson
2021-05-20 23:03 ` [PATCH 12/12] KVM: selftests: Add a test of an unbacked nested PI descriptor Jim Mattson
2021-05-21  0:58 ` [PATCH 00/12] KVM: nVMX: Fix vmcs02 PID use-after-free issue Sean Christopherson
2021-05-21 12:04 ` Jim Mattson
2021-05-24 15:50 ` Paolo Bonzini
2021-05-24 16:46 ` Paolo Bonzini

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