2022-06-06 05:07:02

by Lai Jiangshan

Subject: [PATCH 03/12] KVM: X86/MMU: Split a part of kvm_unsync_page() as kvm_mmu_page_mark_unsync()

From: Lai Jiangshan <[email protected]>

Make it as the opposite function of kvm_mmu_page_clear_unsync().

Signed-off-by: Lai Jiangshan <[email protected]>
---
arch/x86/kvm/mmu/mmu.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index c20981dfc4fd..cc0207e26f6e 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -2529,12 +2529,16 @@ static int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
return r;
}

-static void kvm_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp)
+static void kvm_mmu_page_mark_unsync(struct kvm *kvm, struct kvm_mmu_page *sp)
{
trace_kvm_mmu_unsync_page(sp);
++kvm->stat.mmu_unsync;
sp->unsync = 1;
+}

+static void kvm_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp)
+{
+ kvm_mmu_page_mark_unsync(kvm, sp);
kvm_mmu_mark_parents_unsync(sp);
}

--
2.19.1.6.gb485710b

2022-07-14 22:58:16

by Sean Christopherson

Subject: Re: [PATCH 03/12] KVM: X86/MMU: Split a part of kvm_unsync_page() as kvm_mmu_page_mark_unsync()

On Sun, Jun 05, 2022, Lai Jiangshan wrote:
> From: Lai Jiangshan <[email protected]>
>
> Make it as the opposite function of kvm_mmu_page_clear_unsync().
>
> Signed-off-by: Lai Jiangshan <[email protected]>
> ---
> arch/x86/kvm/mmu/mmu.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index c20981dfc4fd..cc0207e26f6e 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -2529,12 +2529,16 @@ static int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
> return r;
> }
>
> -static void kvm_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp)
> +static void kvm_mmu_page_mark_unsync(struct kvm *kvm, struct kvm_mmu_page *sp)

The existing code is anything but consistent, but I think I prefer the pattern:

kvm_mmu_<action>_<target>_<flag>

I.e. kvm_mmu_mark_page_unsync() + kvm_mmu_unmark_page_unsync() to yield:

kvm_mmu_mark_page_unsync(kvm, sp);
kvm_mmu_mark_parents_unsync(sp);

so that at least this code will be consistent with itself.

> {
> trace_kvm_mmu_unsync_page(sp);
> ++kvm->stat.mmu_unsync;
> sp->unsync = 1;
> +}
>
> +static void kvm_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp)

Rather than keep kvm_unsync_page(), what about just open coding the calls in
mmu_try_to_unsync_pages()? I can't imagine we'll ever have a second caller.

There won't be a direct pair to kvm_sync_page(), but that's not necessarily a bad
thing since they are really direct opposites anyway.

> +{
> + kvm_mmu_page_mark_unsync(kvm, sp);
> kvm_mmu_mark_parents_unsync(sp);
> }
>
> --
> 2.19.1.6.gb485710b
>