From: Sean Christopherson <seanjc@google.com>
To: Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>,
David Woodhouse <dwmw2@infradead.org>,
Paul Durrant <paul@xen.org>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
syzbot+352e553a86e0d75f5120@syzkaller.appspotmail.com,
Paul Durrant <pdurrant@amazon.com>,
David Woodhouse <dwmw@amazon.co.uk>,
Vitaly Kuznetsov <vkuznets@redhat.com>
Subject: [PATCH v2 02/11] KVM: x86: Eliminate "handling" of impossible errors during SUSPEND
Date: Fri, 31 Jan 2025 17:38:18 -0800 [thread overview]
Message-ID: <20250201013827.680235-3-seanjc@google.com> (raw)
In-Reply-To: <20250201013827.680235-1-seanjc@google.com>
Drop KVM's handling of kvm_set_guest_paused() failure when reacting to a
SUSPEND notification, as kvm_set_guest_paused() only "fails" if the vCPU
isn't using kvmclock, and KVM's notifier callback pre-checks that kvmclock
is active. I.e. barring some bizarre edge case that shouldn't be treated
as an error in the first place, kvm_arch_suspend_notifier() can't fail.
Reviewed-by: Paul Durrant <paul@xen.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/x86.c | 20 +++++++-------------
1 file changed, 7 insertions(+), 13 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 26e18c9b0375..ef21158ec6b2 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6905,21 +6905,15 @@ static int kvm_arch_suspend_notifier(struct kvm *kvm)
{
struct kvm_vcpu *vcpu;
unsigned long i;
- int ret = 0;
- kvm_for_each_vcpu(i, vcpu, kvm) {
- if (!vcpu->arch.pv_time.active)
- continue;
+ /*
+ * Ignore the return, marking the guest paused only "fails" if the vCPU
+ * isn't using kvmclock; continuing on is correct and desirable.
+ */
+ kvm_for_each_vcpu(i, vcpu, kvm)
+ (void)kvm_set_guest_paused(vcpu);
- ret = kvm_set_guest_paused(vcpu);
- if (ret) {
- kvm_err("Failed to pause guest VCPU%d: %d\n",
- vcpu->vcpu_id, ret);
- break;
- }
- }
-
- return ret ? NOTIFY_BAD : NOTIFY_DONE;
+ return NOTIFY_DONE;
}
int kvm_arch_pm_notifier(struct kvm *kvm, unsigned long state)
--
2.48.1.362.g079036d154-goog
next prev parent reply other threads:[~2025-02-01 1:38 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-01 1:38 [PATCH v2 00/11] KVM: x86: pvclock fixes and cleanups Sean Christopherson
2025-02-01 1:38 ` [PATCH v2 01/11] KVM: x86: Don't take kvm->lock when iterating over vCPUs in suspend notifier Sean Christopherson
2025-02-01 1:38 ` Sean Christopherson [this message]
2025-02-01 1:38 ` [PATCH v2 03/11] KVM: x86: Drop local pvclock_flags variable in kvm_guest_time_update() Sean Christopherson
2025-02-01 1:38 ` [PATCH v2 04/11] KVM: x86: Process "guest stopped request" once per guest time update Sean Christopherson
2025-02-04 9:19 ` Paul Durrant
2025-02-01 1:38 ` [PATCH v2 05/11] KVM: x86/xen: Use guest's copy of pvclock when starting timer Sean Christopherson
2025-02-04 9:26 ` Paul Durrant
2025-02-01 1:38 ` [PATCH v2 06/11] KVM: x86: Don't bleed PVCLOCK_GUEST_STOPPED across PV clocks Sean Christopherson
2025-02-04 9:28 ` Paul Durrant
2025-02-01 1:38 ` [PATCH v2 07/11] KVM: x86: Set PVCLOCK_GUEST_STOPPED only for kvmclock, not for Xen PV clock Sean Christopherson
2025-02-04 9:31 ` Paul Durrant
2025-02-01 1:38 ` [PATCH v2 08/11] KVM: x86: Pass reference pvclock as a param to kvm_setup_guest_pvclock() Sean Christopherson
2025-02-04 9:33 ` Paul Durrant
2025-02-04 9:38 ` Paul Durrant
2025-02-04 19:23 ` Sean Christopherson
2025-02-01 1:38 ` [PATCH v2 09/11] KVM: x86: Remove per-vCPU "cache" of its reference pvclock Sean Christopherson
2025-02-01 1:38 ` [PATCH v2 10/11] KVM: x86: Setup Hyper-V TSC page before Xen PV clocks (during clock update) Sean Christopherson
2025-02-01 1:38 ` [PATCH v2 11/11] KVM: x86: Override TSC_STABLE flag for Xen PV clocks in kvm_guest_time_update() Sean Christopherson
2025-02-15 0:50 ` [PATCH v2 00/11] KVM: x86: pvclock fixes and cleanups Sean Christopherson
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=20250201013827.680235-3-seanjc@google.com \
--to=seanjc@google.com \
--cc=dwmw2@infradead.org \
--cc=dwmw@amazon.co.uk \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=paul@xen.org \
--cc=pbonzini@redhat.com \
--cc=pdurrant@amazon.com \
--cc=syzbot+352e553a86e0d75f5120@syzkaller.appspotmail.com \
--cc=vkuznets@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
all inboxes | Powered by JetHome®