Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-12-14 15:13:52 +00:00
Code Issues Packages Projects Releases Wiki Activity

KVM: x86/mmu: Decompose kvm_mmu_get_page() into separate functions

Browse Source 
Decompose kvm_mmu_get_page() into separate helper functions to increase
readability and prepare for allocating shadow pages without a vcpu
pointer.

Specifically, pull the guts of kvm_mmu_get_page() into 2 helper
functions:

kvm_mmu_find_shadow_page() -
  Walks the page hash checking for any existing mmu pages that match the
  given gfn and role.

kvm_mmu_alloc_shadow_page()
  Allocates and initializes an entirely new kvm_mmu_page. This currently
  requries a vcpu pointer for allocation and looking up the memslot but
  that will be removed in a future commit.

No functional change intended.

Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <20220516232138.1783324-7-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
David Matlack 2022-06-22 15:26:53 -04:00 committed by Paolo Bonzini
parent 7f49777550
commit 94c8136448
1 changed files with 39 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

52
arch/x86/kvm/mmu/mmu.c
View File

@ -1993,16 +1993,16 @@ static void clear_sp_write_flooding_count(u64 *spte)
__clear_sp_write_flooding_count(sptep_to_sp(spte));
}
static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, gfn_t gfn,
union kvm_mmu_page_role role)
static struct kvm_mmu_page *kvm_mmu_find_shadow_page(struct kvm_vcpu *vcpu,
gfn_t gfn,
struct hlist_head *sp_list,
union kvm_mmu_page_role role)
{
struct hlist_head *sp_list;
struct kvm_mmu_page *sp;
int ret;
int collisions = 0;
LIST_HEAD(invalid_list);
sp_list = &vcpu->kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)];
for_each_valid_sp(vcpu->kvm, sp, sp_list) {
if (sp->gfn != gfn) {
collisions++;
@ -2027,7 +2027,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, gfn_t gfn,
/* unsync and write-flooding only apply to indirect SPs. */
if (sp->role.direct)
goto trace_get_page;
goto out;
if (sp->unsync) {
/*
@ -2053,14 +2053,26 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, gfn_t gfn,
__clear_sp_write_flooding_count(sp);
trace_get_page:
trace_kvm_mmu_get_page(sp, false);
goto out;
}
sp = NULL;
++vcpu->kvm->stat.mmu_cache_miss;
sp = kvm_mmu_alloc_page(vcpu, role.direct);
out:
kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);
if (collisions > vcpu->kvm->stat.max_mmu_page_hash_collisions)
vcpu->kvm->stat.max_mmu_page_hash_collisions = collisions;
return sp;
}
static struct kvm_mmu_page *kvm_mmu_alloc_shadow_page(struct kvm_vcpu *vcpu,
gfn_t gfn,
struct hlist_head *sp_list,
union kvm_mmu_page_role role)
{
struct kvm_mmu_page *sp = kvm_mmu_alloc_page(vcpu, role.direct);
sp->gfn = gfn;
sp->role = role;
@ -2070,12 +2082,26 @@ trace_get_page:
if (role.level == PG_LEVEL_4K && kvm_vcpu_write_protect_gfn(vcpu, gfn))
kvm_flush_remote_tlbs_with_address(vcpu->kvm, gfn, 1);
}
trace_kvm_mmu_get_page(sp, true);
out:
kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);
if (collisions > vcpu->kvm->stat.max_mmu_page_hash_collisions)
vcpu->kvm->stat.max_mmu_page_hash_collisions = collisions;
return sp;
}
static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, gfn_t gfn,
union kvm_mmu_page_role role)
{
struct hlist_head *sp_list;
struct kvm_mmu_page *sp;
bool created = false;
sp_list = &vcpu->kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)];
sp = kvm_mmu_find_shadow_page(vcpu, gfn, sp_list, role);
if (!sp) {
created = true;
sp = kvm_mmu_alloc_shadow_page(vcpu, gfn, sp_list, role);
}
trace_kvm_mmu_get_page(sp, created);
return sp;
}