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KVM: x86/mmu: Decrease indentation in logic to sync new indirect shadow page

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Combine the back-to-back if-statements for synchronizing children when
linking a new indirect shadow page in order to decrease the indentation,
and to make it easier to "see" the logic in its entirety.

No functional change intended.

Link: https://lore.kernel.org/r/20240802203900.348808-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
This commit is contained in:
Sean Christopherson 2024-08-02 13:38:58 -07:00
parent acf2923271
commit 174b6e4a25
1 changed files with 19 additions and 21 deletions
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40
arch/x86/kvm/mmu/paging_tmpl.h
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@ -674,27 +674,25 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault,
sp = kvm_mmu_get_child_sp(vcpu, it.sptep, table_gfn,
false, access);
if (sp != ERR_PTR(-EEXIST)) {
/*
* We must synchronize the pagetable before linking it
* because the guest doesn't need to flush tlb when
* the gpte is changed from non-present to present.
* Otherwise, the guest may use the wrong mapping.
*
* For PG_LEVEL_4K, kvm_mmu_get_page() has already
* synchronized it transiently via kvm_sync_page().
*
* For higher level pagetable, we synchronize it via
* the slower mmu_sync_children(). If it needs to
* break, some progress has been made; return
* RET_PF_RETRY and retry on the next #PF.
* KVM_REQ_MMU_SYNC is not necessary but it
* expedites the process.
*/
if (sp->unsync_children &&
mmu_sync_children(vcpu, sp, false))
return RET_PF_RETRY;
}
/*
* Synchronize the new page before linking it, as the CPU (KVM)
* is architecturally disallowed from inserting non-present
* entries into the TLB, i.e. the guest isn't required to flush
* the TLB when changing the gPTE from non-present to present.
*
* For PG_LEVEL_4K, kvm_mmu_find_shadow_page() has already
* synchronized the page via kvm_sync_page().
*
* For higher level pages, which cannot be unsync themselves
* but can have unsync children, synchronize via the slower
* mmu_sync_children(). If KVM needs to drop mmu_lock due to
* contention or to reschedule, instruct the caller to retry
* the #PF (mmu_sync_children() ensures forward progress will
* be made).
*/
if (sp != ERR_PTR(-EEXIST) && sp->unsync_children &&
mmu_sync_children(vcpu, sp, false))
return RET_PF_RETRY;
/*
* Verify that the gpte in the page we've just write