[PATCH v4 01/20] KVM: x86/mmu: Optimize MMU page cache lookup for all direct SPs

Lai Jiangshan jiangshanlai at gmail.com
Sat May 7 00:46:19 PDT 2022

On 2022/4/23 05:05, David Matlack wrote:
> Commit fb58a9c345f6 ("KVM: x86/mmu: Optimize MMU page cache lookup for
> fully direct MMUs") skipped the unsync checks and write flood clearing
> for full direct MMUs. We can extend this further to skip the checks for
> all direct shadow pages. Direct shadow pages in indirect MMUs (i.e.
> shadow paging) are used when shadowing a guest huge page with smaller
> pages. Such direct shadow pages, like their counterparts in fully direct
> MMUs, are never marked unsynced or have a non-zero write-flooding count.
> Checking sp->role.direct also generates better code than checking
> direct_map because, due to register pressure, direct_map has to get
> shoved onto the stack and then pulled back off.
> No functional change intended.
> Reviewed-by: Sean Christopherson <seanjc at google.com>
> Reviewed-by: Peter Xu <peterx at redhat.com>
> Signed-off-by: David Matlack <dmatlack at google.com>

Reviewed-by: Lai Jiangshan <jiangshanlai at gmail.com>

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