Kernel/linux-next
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git synced 2024-12-29 09:12:07 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

KVM: x86/mmu: Drop per-VM zapped_obsolete_pages list

Browse Source 
Drop the per-VM zapped_obsolete_pages list now that the usage from the
defunct mmu_shrinker is gone, and instead use a local list to track pages
in kvm_zap_obsolete_pages(), the sole remaining user of
zapped_obsolete_pages.

Opportunistically add an assertion to verify and document that slots_lock
must be held, i.e. that there can only be one active instance of
kvm_zap_obsolete_pages() at any given time, and by doing so also prove
that using a local list instead of a per-VM list doesn't change any
functionality (beyond trivialities like list initialization).

Signed-off-by: Vipin Sharma <vipinsh@google.com>
Link: https://lore.kernel.org/r/20241101201437.1604321-2-vipinsh@google.com
[sean: split to separate patch, write changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
This commit is contained in:
Vipin Sharma 2024-11-01 13:14:37 -07:00 committed by Sean Christopherson
parent fe140e611d
commit 4cf20d4254
2 changed files with 5 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/x86/include/asm/kvm_host.h
View File

@ -1306,7 +1306,6 @@ struct kvm_arch {
bool pre_fault_allowed;
struct hlist_head mmu_page_hash[KVM_NUM_MMU_PAGES];
struct list_head active_mmu_pages;
struct list_head zapped_obsolete_pages;
/*
* A list of kvm_mmu_page structs that, if zapped, could possibly be
* replaced by an NX huge page. A shadow page is on this list if its

8
arch/x86/kvm/mmu/mmu.c
View File

@ -6367,8 +6367,11 @@ static void kvm_zap_obsolete_pages(struct kvm *kvm)
{
struct kvm_mmu_page *sp, *node;
int nr_zapped, batch = 0;
LIST_HEAD(invalid_list);
bool unstable;
lockdep_assert_held(&kvm->slots_lock);
restart:
list_for_each_entry_safe_reverse(sp, node,
&kvm->arch.active_mmu_pages, link) {
@ -6400,7 +6403,7 @@ static void kvm_zap_obsolete_pages(struct kvm *kvm)
}
unstable = __kvm_mmu_prepare_zap_page(kvm, sp,
&kvm->arch.zapped_obsolete_pages, &nr_zapped);
&invalid_list, &nr_zapped);
batch += nr_zapped;
if (unstable)
@ -6416,7 +6419,7 @@ static void kvm_zap_obsolete_pages(struct kvm *kvm)
* kvm_mmu_load()), and the reload in the caller ensure no vCPUs are
* running with an obsolete MMU.
*/
kvm_mmu_commit_zap_page(kvm, &kvm->arch.zapped_obsolete_pages);
kvm_mmu_commit_zap_page(kvm, &invalid_list);
}
/*
@ -6483,7 +6486,6 @@ void kvm_mmu_init_vm(struct kvm *kvm)
{
kvm->arch.shadow_mmio_value = shadow_mmio_value;
INIT_LIST_HEAD(&kvm->arch.active_mmu_pages);
INIT_LIST_HEAD(&kvm->arch.zapped_obsolete_pages);
INIT_LIST_HEAD(&kvm->arch.possible_nx_huge_pages);
spin_lock_init(&kvm->arch.mmu_unsync_pages_lock);