From: Paolo Bonzini <pbonzini@redhat.com>
To: Hikaru Nishida <hikalium@chromium.org>,
linux-kernel@vger.kernel.org, dme@dme.org, tglx@linutronix.de,
mlevitsk@redhat.com
Cc: suleiman@google.com, Borislav Petkov <bp@alien8.de>,
"H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
John Stultz <john.stultz@linaro.org>,
Sean Christopherson <seanjc@google.com>,
Stephen Boyd <sboyd@kernel.org>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
kvm@vger.kernel.org, x86@kernel.org
Subject: Re: [v2 PATCH 3/4] x86/kvm: Add host side support for virtual suspend time injection
Date: Sat, 14 Aug 2021 09:22:18 +0200 [thread overview]
Message-ID: <2ec642dd-dde6-bee6-3de3-0fa78d288995@redhat.com> (raw)
In-Reply-To: <20210806190607.v2.3.Ib0cb8ecae99f0ccd0e2814b310adba00b9e81d94@changeid>
On 06/08/21 12:07, Hikaru Nishida wrote:
> +#if defined(CONFIG_KVM_VIRT_SUSPEND_TIMING) || \
> + defined(CONFIG_KVM_VIRT_SUSPEND_TIMING_GUEST)
> +#define VIRT_SUSPEND_TIMING_VECTOR 0xec
> +#endif
No need to use a new vector. You can rename the existing
MSR_KVM_ASYNC_PF_INT to MSR_KVM_HYPERVISOR_CALLBACK_INT or something
like that, and add the code to sysvec_kvm_asyncpf_interrupt.
> +static void kvm_make_suspend_time_interrupt(struct kvm_vcpu *vcpu)
> +{
> + kvm_queue_interrupt(vcpu, VIRT_SUSPEND_TIMING_VECTOR, false);
> + kvm_make_request(KVM_REQ_EVENT, vcpu);
> +}
Use kvm_apic_set_irq which will inject the interrupt as soon as
possible, so you do not even need to check
kvm_vcpu_ready_for_interrupt_injection.
> +#ifdef CONFIG_KVM_VIRT_SUSPEND_TIMING
> + if (kvm->suspend_injection_requested &&
> + kvm_vcpu_ready_for_interrupt_injection(vcpu)) {
> + kvm_write_suspend_time(kvm);
> + kvm_make_suspend_time_interrupt(vcpu);
> + kvm->suspend_injection_requested = false;
> + }
> +#endif
Do not read variables in vcpu_run; There is KVM_REQ_* if you need to do
work in the vCPU run loop.
> + mutex_lock(&kvm_lock);
> + list_for_each_entry(kvm, &vm_list, vm_list) {
> + if (!(kvm->arch.msr_suspend_time & KVM_MSR_ENABLED))
> + continue;
> +
> + kvm_for_each_vcpu(i, vcpu, kvm)
> + vcpu->arch.tsc_offset_adjustment -= adj;
> +
> + /*
> + * Move the offset of kvm_clock here as if it is stopped
> + * during the suspension.
> + */
> + kvm->arch.kvmclock_offset -= suspend_time_ns;
> +
> + /* suspend_time is accumulated per VM. */
> + kvm->suspend_time_ns += suspend_time_ns;
> + kvm->suspend_injection_requested = true;
> + /*
> + * This adjustment will be reflected to the struct provided
> + * from the guest via MSR_KVM_HOST_SUSPEND_TIME before
> + * the notification interrupt is injected.
> + */
> + }
> + mutex_unlock(&kvm_lock);
> +}
As pointed out by Thomas, this should be a work item.
Paolo
next prev parent reply other threads:[~2021-08-14 7:22 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-06 10:07 [v2 PATCH 0/4] x86/kvm: Virtual suspend time injection support Hikaru Nishida
2021-08-06 10:07 ` [v2 PATCH 1/4] x86/kvm: Reserve KVM_FEATURE_HOST_SUSPEND_TIME and MSR_KVM_HOST_SUSPEND_TIME Hikaru Nishida
2021-08-06 10:07 ` [v2 PATCH 2/4] x86/kvm: Add definitions for virtual suspend time injection Hikaru Nishida
2021-08-10 15:14 ` Thomas Gleixner
2021-08-13 18:36 ` Guenter Roeck
2021-08-06 10:07 ` [v2 PATCH 3/4] x86/kvm: Add host side support " Hikaru Nishida
2021-08-10 15:21 ` Thomas Gleixner
2021-08-10 15:24 ` Thomas Gleixner
2021-08-14 7:22 ` Paolo Bonzini [this message]
2021-08-18 9:32 ` Vitaly Kuznetsov
2021-08-18 20:49 ` Paolo Bonzini
2021-08-06 10:07 ` [v2 PATCH 4/4] x86/kvm: Add guest " Hikaru Nishida
2021-08-10 15:48 ` Thomas Gleixner
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