kvm.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jim Mattson <jmattson@google.com>
To: kvm@vger.kernel.org, pbonzini@redhat.com
Cc: Jim Mattson <jmattson@google.com>
Subject: [PATCH v2 06/12] KVM: nVMX: Fail on MMIO completion for nested posted interrupts
Date: Fri,  4 Jun 2021 10:26:05 -0700	[thread overview]
Message-ID: <20210604172611.281819-7-jmattson@google.com> (raw)
In-Reply-To: <20210604172611.281819-1-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,
-- 
2.32.0.rc1.229.g3e70b5a671-goog


  parent reply	other threads:[~2021-06-04 17:27 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-04 17:25 [PATCH v2 00/12] KVM: nVMX: Fix vmcs02 PID use-after-free issue Jim Mattson
2021-06-04 17:26 ` [PATCH v2 01/12] KVM: x86: Remove guest mode check from kvm_check_nested_events Jim Mattson
2021-06-04 17:26 ` [PATCH v2 02/12] KVM: x86: Wake up a vCPU when kvm_check_nested_events fails Jim Mattson
2021-06-04 17:26 ` [PATCH v2 03/12] KVM: nVMX: Add a return code to vmx_complete_nested_posted_interrupt Jim Mattson
2021-06-04 17:26 ` [PATCH v2 04/12] KVM: x86: Add a return code to inject_pending_event Jim Mattson
2021-06-04 17:26 ` [PATCH v2 05/12] KVM: x86: Add a return code to kvm_apic_accept_events Jim Mattson
2021-06-04 17:26 ` Jim Mattson [this message]
2021-06-04 17:26 ` [PATCH v2 07/12] KVM: nVMX: Disable vmcs02 posted interrupts if vmcs12 PID isn't mappable Jim Mattson
2021-06-04 17:26 ` [PATCH v2 08/12] KVM: selftests: Move APIC definitions into a separate file Jim Mattson
2021-06-04 17:26 ` [PATCH v2 09/12] KVM: selftests: Hoist APIC functions out of individual tests Jim Mattson
2021-06-04 17:26 ` [PATCH v2 10/12] KVM: selftests: Introduce x2APIC register manipulation functions Jim Mattson
2021-06-04 17:26 ` [PATCH v2 11/12] KVM: selftests: Introduce prepare_tpr_shadow Jim Mattson
2021-06-04 17:26 ` [PATCH v2 12/12] KVM: selftests: Add a test of an unbacked nested PI descriptor Jim Mattson
2021-06-10 11:55 ` [PATCH v2 00/12] KVM: nVMX: Fix vmcs02 PID use-after-free issue Paolo Bonzini

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210604172611.281819-7-jmattson@google.com \
    --to=jmattson@google.com \
    --cc=kvm@vger.kernel.org \
    --cc=pbonzini@redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).