On Wed, 2022-08-31 at 00:34 +0000, Sean Christopherson wrote:
> Drop the redundant "cluster" calculation and its horrific shadowing in
> the x2avic logical mode path. The "cluster" that is declared at an outer
> scope is derived using the exact same calculation and has performed the
> left-shift.
Actually I think we should just revert the commit
'KVM: SVM: Use target APIC ID to complete x2AVIC IRQs when possible'
I know that the patch that intially introduced the the avic_kick_target_vcpus_fast had
x2apic/x2avic code, and then it was split to avoid adding x2avic code before it was merged,
resulting in this patch to add the x2apic specific code.
But when I fixed most issues of avic_kick_target_vcpus_fast in my
'KVM: x86: SVM: fix avic_kick_target_vcpus_fast', I added back x2apic code because
it was just natural to do since I had to calculate cluster/bitmap masks anyway.
I expected this patch to be dropped because of this but I guess it was not noticed,
or patches were merged in the wrong order.
This is the reason of shadowing, duplicate calculations/etc.
Patch 9 and 7 of your series can be dropped as well then.
Best regards,
Maxim Levitsky
>
> No functional change intended.
>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
> arch/x86/kvm/svm/avic.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
> index 14f567550a1e..8c9cad96008e 100644
> --- a/arch/x86/kvm/svm/avic.c
> +++ b/arch/x86/kvm/svm/avic.c
> @@ -410,10 +410,9 @@ static int avic_kick_target_vcpus_fast(struct kvm *kvm, struct kvm_lapic *source
> * For x2APIC logical mode, cannot leverage the index.
> * Instead, calculate physical ID from logical ID in ICRH.
> */
> - int cluster = (icrh & 0xffff0000) >> 16;
> int apic = ffs(bitmap) - 1;
>
> - l1_physical_id = (cluster << 4) + apic;
> + l1_physical_id = cluster + apic;
> }
> }
>