From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
mlevitsk@redhat.com, vkuznets@redhat.com
Subject: Re: [PATCH v2 8/9] KVM: x86: lapic does not have to process INIT if it is blocked
Date: Wed, 17 Aug 2022 00:07:03 +0000 [thread overview]
Message-ID: <YvwxJzHC5xYnc7CJ@google.com> (raw)
In-Reply-To: <20220811210605.402337-9-pbonzini@redhat.com>
On Thu, Aug 11, 2022, Paolo Bonzini wrote:
> Do not return true from kvm_apic_has_events, and consequently from
> kvm_vcpu_has_events, if the vCPU is not going to process an INIT.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> arch/x86/include/asm/kvm_host.h | 1 +
> arch/x86/kvm/i8259.c | 2 +-
> arch/x86/kvm/lapic.h | 2 +-
> arch/x86/kvm/x86.c | 5 +++++
> arch/x86/kvm/x86.h | 5 -----
> 5 files changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 293ff678fff5..1ce4ebc41118 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -2042,6 +2042,7 @@ void __user *__x86_set_memory_region(struct kvm *kvm, int id, gpa_t gpa,
> u32 size);
> bool kvm_vcpu_is_reset_bsp(struct kvm_vcpu *vcpu);
> bool kvm_vcpu_is_bsp(struct kvm_vcpu *vcpu);
> +bool kvm_vcpu_latch_init(struct kvm_vcpu *vcpu);
>
> bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
> struct kvm_vcpu **dest_vcpu);
> diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
> index e1bb6218bb96..177555eea54e 100644
> --- a/arch/x86/kvm/i8259.c
> +++ b/arch/x86/kvm/i8259.c
> @@ -29,9 +29,9 @@
> #include <linux/mm.h>
> #include <linux/slab.h>
> #include <linux/bitops.h>
> -#include "irq.h"
> +#include <linux/kvm_host.h>
>
> -#include <linux/kvm_host.h>
> +#include "irq.h"
> #include "trace.h"
>
> #define pr_pic_unimpl(fmt, ...) \
> diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
> index 117a46df5cc1..12577ddccdfc 100644
> --- a/arch/x86/kvm/lapic.h
> +++ b/arch/x86/kvm/lapic.h
> @@ -225,7 +225,7 @@ static inline bool kvm_vcpu_apicv_active(struct kvm_vcpu *vcpu)
>
> static inline bool kvm_apic_has_events(struct kvm_vcpu *vcpu)
> {
> - return lapic_in_kernel(vcpu) && vcpu->arch.apic->pending_events;
> + return lapic_in_kernel(vcpu) && vcpu->arch.apic->pending_events && !kvm_vcpu_latch_init(vcpu);
Blech, the kvm_apic_has_events() name is awful (as is pending_events), e.g. it
really should be kvm_apic_has_pending_sipi_or_init().
To avoid the odd kvm_vcpu_latch_init() declaration and the long line above, what
if we open code this in kvm_vcpu_has_events() like we do for NMI, SMI, etc...?
And as follow-up, I would love to rename kvm_vcpu_latch_init() => kvm_vcpu_init_blocked(),
kvm_apic_has_events(), and pending_events.
E.g. for this patch just do:
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9f11b505cbee..559900736a71 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -12533,7 +12533,8 @@ static inline bool kvm_vcpu_has_events(struct kvm_vcpu *vcpu)
if (!list_empty_careful(&vcpu->async_pf.done))
return true;
- if (kvm_apic_has_events(vcpu))
+ /* comment explaning that SIPIs are dropped in this case. */
+ if (kvm_apic_has_events(vcpu) && !kvm_vcpu_latch_init(vcpu))
return true;
if (vcpu->arch.pv.pv_unhalted)
next prev parent reply other threads:[~2022-08-17 0:07 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-11 21:05 [PATCH v2 0/9] KVM: x86: never write to memory from kvm_vcpu_check_block Paolo Bonzini
2022-08-11 21:05 ` [PATCH v2 1/9] KVM: x86: check validity of argument to KVM_SET_MP_STATE Paolo Bonzini
2022-08-15 13:31 ` Maxim Levitsky
2022-08-16 22:50 ` Sean Christopherson
2022-08-11 21:05 ` [PATCH v2 2/9] KVM: x86: remove return value of kvm_vcpu_block Paolo Bonzini
2022-08-16 23:34 ` Sean Christopherson
2022-08-17 14:10 ` Maxim Levitsky
2022-08-17 15:31 ` Paolo Bonzini
2022-08-17 16:41 ` Sean Christopherson
2022-08-17 16:49 ` Paolo Bonzini
2022-09-20 0:42 ` Sean Christopherson
2022-08-11 21:05 ` [PATCH v2 3/9] KVM: x86: make kvm_vcpu_{block,halt} return whether vCPU is runnable Paolo Bonzini
2022-08-11 21:06 ` [PATCH v2 4/9] KVM: mips, x86: do not rely on KVM_REQ_UNHALT Paolo Bonzini
2022-08-11 21:06 ` [PATCH v2 5/9] KVM: remove KVM_REQ_UNHALT Paolo Bonzini
2022-08-11 21:06 ` [PATCH v2 6/9] KVM: x86: make vendor code check for all nested events Paolo Bonzini
2022-08-16 23:47 ` Sean Christopherson
2022-08-17 14:10 ` Maxim Levitsky
2022-08-11 21:06 ` [PATCH v2 7/9] KVM: nVMX: Make an event request when pending an MTF nested VM-Exit Paolo Bonzini
2022-08-17 14:11 ` Maxim Levitsky
2022-08-11 21:06 ` [PATCH v2 8/9] KVM: x86: lapic does not have to process INIT if it is blocked Paolo Bonzini
2022-08-17 0:07 ` Sean Christopherson [this message]
2022-08-17 14:11 ` Maxim Levitsky
2022-08-17 15:33 ` Paolo Bonzini
2022-08-11 21:06 ` [PATCH v2 9/9] KVM: x86: never write to memory from kvm_vcpu_check_block Paolo Bonzini
2022-08-16 23:45 ` Sean Christopherson
2022-08-17 14:11 ` Maxim Levitsky
2022-09-20 0:32 ` Sean Christopherson
2022-09-20 0:55 ` Sean Christopherson
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