Commit 1148bfc4 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: x86/mmu: Move lpage_disallowed_link further "down" in kvm_mmu_page 



Move "lpage_disallowed_link" out of the first 64 bytes, i.e. out of the
first cache line, of kvm_mmu_page so that "spt" and to a lesser extent
"gfns" land in the first cache line.  "lpage_disallowed_link" is accessed
relatively infrequently compared to "spt", which is accessed any time KVM
is walking and/or manipulating the shadow page tables.

No functional change intended.

Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20210901221023.1303578-4-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent ca41c34c

arch/x86/kvm/mmu/mmu_internal.h

+5 −1
Original line number Diff line number Diff line
@@ -31,9 +31,12 @@ extern bool dbg; 
#define IS_VALID_PAE_ROOT(x)	(!!(x))



struct kvm_mmu_page {

	/*

	 * Note, "link" through "spt" fit in a single 64 byte cache line on

	 * 64-bit kernels, keep it that way unless there's a reason not to.

	 */

	struct list_head link;

	struct hlist_node hash_link;

	struct list_head lpage_disallowed_link;



	bool tdp_mmu_page;

	bool unsync;
@@ -59,6 +62,7 @@ struct kvm_mmu_page { 
	struct kvm_rmap_head parent_ptes; /* rmap pointers to parent sptes */

	DECLARE_BITMAP(unsync_child_bitmap, 512);



	struct list_head lpage_disallowed_link;

#ifdef CONFIG_X86_32

	/*

	 * Used out of the mmu-lock to avoid reading spte values while an