From: Andrew Jones <drjones@redhat.com>
To: kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu
Cc: pbonzini@redhat.com, steven.price@arm.com, maz@kernel.org
Subject: [PATCH 2/5] KVM: arm64: pvtime: Fix potential loss of stolen time
Date: Sat, 11 Jul 2020 12:04:31 +0200 [thread overview]
Message-ID: <20200711100434.46660-3-drjones@redhat.com> (raw)
In-Reply-To: <20200711100434.46660-1-drjones@redhat.com>
We should only check current->sched_info.run_delay once when
updating stolen time. Otherwise there's a chance there could
be a change between checks that we miss (preemption disabling
comes after vcpu request checks).
Signed-off-by: Andrew Jones <drjones@redhat.com>
---
arch/arm64/kvm/pvtime.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/pvtime.c b/arch/arm64/kvm/pvtime.c
index 2b22214909be..db5ef097a166 100644
--- a/arch/arm64/kvm/pvtime.c
+++ b/arch/arm64/kvm/pvtime.c
@@ -13,6 +13,7 @@
void kvm_update_stolen_time(struct kvm_vcpu *vcpu)
{
struct kvm *kvm = vcpu->kvm;
+ u64 last_steal = vcpu->arch.steal.last_steal;
u64 steal;
__le64 steal_le;
u64 offset;
@@ -24,8 +25,8 @@ void kvm_update_stolen_time(struct kvm_vcpu *vcpu)
/* Let's do the local bookkeeping */
steal = vcpu->arch.steal.steal;
- steal += current->sched_info.run_delay - vcpu->arch.steal.last_steal;
vcpu->arch.steal.last_steal = current->sched_info.run_delay;
+ steal += vcpu->arch.steal.last_steal - last_steal;
vcpu->arch.steal.steal = steal;
steal_le = cpu_to_le64(steal);
--
2.25.4
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
next prev parent reply other threads:[~2020-07-11 10:04 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-11 10:04 [PATCH 0/5] KVM: arm64: pvtime: Fixes and a new cap Andrew Jones
2020-07-11 10:04 ` [PATCH 1/5] KVM: arm64: pvtime: steal-time is only supported when configured Andrew Jones
2020-07-27 17:25 ` Marc Zyngier
2020-07-28 12:55 ` Andrew Jones
2020-07-28 13:13 ` Marc Zyngier
2020-07-28 13:29 ` Andrew Jones
2020-07-11 10:04 ` Andrew Jones [this message]
2020-07-27 17:29 ` [PATCH 2/5] KVM: arm64: pvtime: Fix potential loss of stolen time Marc Zyngier
2020-07-11 10:04 ` [PATCH 3/5] KVM: arm64: pvtime: Fix stolen time accounting across migration Andrew Jones
2020-07-27 17:54 ` Marc Zyngier
2020-07-11 10:04 ` [PATCH 4/5] KVM: Documentation minor fixups Andrew Jones
2020-07-27 17:55 ` Marc Zyngier
2020-07-11 10:04 ` [PATCH 5/5] arm64/x86: KVM: Introduce steal-time cap Andrew Jones
2020-07-27 17:58 ` Marc Zyngier
2020-07-11 10:20 ` [PATCH 0/5] KVM: arm64: pvtime: Fixes and a new cap Andrew Jones
2020-07-13 8:25 ` Steven Price
2020-07-27 11:02 ` Andrew Jones
2020-07-27 11:15 ` Marc Zyngier
2020-07-27 18:01 ` Marc Zyngier
2020-07-28 12:59 ` Andrew Jones
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=20200711100434.46660-3-drjones@redhat.com \
--to=drjones@redhat.com \
--cc=kvm@vger.kernel.org \
--cc=kvmarm@lists.cs.columbia.edu \
--cc=maz@kernel.org \
--cc=pbonzini@redhat.com \
--cc=steven.price@arm.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).