From: "Liu, Jing2" <jing2.liu@linux.intel.com>
To: Sean Christopherson <sean.j.christopherson@intel.com>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Derek Yerger <derek@djy.llc>,
kernel@najdan.com, Thomas Lambertz <mail@thomaslambertz.de>,
Rik van Riel <riel@surriel.com>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Borislav Petkov <bp@suse.de>, Dave Hansen <dave.hansen@intel.com>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH 3/4] KVM: x86: Revert "KVM: X86: Fix fpu state crash in kvm guest"
Date: Wed, 4 Mar 2020 15:41:58 +0800 [thread overview]
Message-ID: <ca47fce8-a042-f967-513c-93cabac2122d@linux.intel.com> (raw)
In-Reply-To: <20200117062628.6233-4-sean.j.christopherson@intel.com>
On 1/17/2020 2:26 PM, Sean Christopherson wrote:
> @@ -8198,8 +8194,9 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
> trace_kvm_entry(vcpu->vcpu_id);
> guest_enter_irqoff();
>
> - /* The preempt notifier should have taken care of the FPU already. */
> - WARN_ON_ONCE(test_thread_flag(TIF_NEED_FPU_LOAD));
> + fpregs_assert_state_consistent();
> + if (test_thread_flag(TIF_NEED_FPU_LOAD))
> + switch_fpu_return();
>
> if (unlikely(vcpu->arch.switch_db_regs)) {
> set_debugreg(0, 7);
Can kvm be preempt out again after this (before really enter to guest)?
Thanks,
Jing
next prev parent reply other threads:[~2020-03-04 7:42 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-17 6:26 [PATCH 0/4] KVM: x86: TIF_NEED_FPU_LOAD bug fixes Sean Christopherson
2020-01-17 6:26 ` [PATCH 1/4] KVM: x86: Handle TIF_NEED_FPU_LOAD in kvm_{load,put}_guest_fpu() Sean Christopherson
2020-01-17 18:31 ` Dave Hansen
2020-01-17 18:43 ` Sean Christopherson
2020-01-17 6:26 ` [PATCH 2/4] KVM: x86: Ensure guest's FPU state is loaded when accessing for emulation Sean Christopherson
2020-01-17 6:26 ` [PATCH 3/4] KVM: x86: Revert "KVM: X86: Fix fpu state crash in kvm guest" Sean Christopherson
2020-03-04 7:41 ` Liu, Jing2 [this message]
2020-03-04 7:58 ` Paolo Bonzini
2020-01-17 6:26 ` [PATCH 4/4] KVM: x86: Remove unused ctxt param from emulator's FPU accessors Sean Christopherson
2020-03-04 7:38 ` [PATCH 0/4] KVM: x86: TIF_NEED_FPU_LOAD bug fixes Liu, Jing2
2020-03-04 15:24 ` Sean Christopherson
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