Guests worked normally in shadow paging mode (ept=0) on my test machine.
Please check if the first two patches reflect what you meant correctly.
Takuya Yoshikawa (3):
[1] KVM: x86: MMU: Move parent_pte handling from kvm_mmu_get_page() to link_shadow_page()
[2] KVM: x86: MMU: Use for_each_rmap_spte macro instead of pte_list_walk()
[3] KVM: x86: MMU: Remove unused parameter parent_pte from kvm_mmu_get_page()
arch/x86/kvm/mmu.c | 70 +++++++++++++++-------------------------------
arch/x86/kvm/paging_tmpl.h | 10 +++----
2 files changed, 26 insertions(+), 54 deletions(-)
--
2.1.0
Every time kvm_mmu_get_page() is called with a non-NULL parent_pte
argument, link_shadow_page() follows that to set the parent entry so
that the new mapping will point to the returned page table.
Moving parent_pte handling there allows to clean up the code because
parent_pte is passed to kvm_mmu_get_page() just for mark_unsync() and
mmu_page_add_parent_pte().
In addition, the patch avoids calling mark_unsync() for other parents in
the sp->parent_ptes chain than the newly added parent_pte, because they
have been there since before the current page fault handling started.
Signed-off-by: Takuya Yoshikawa <[email protected]>
Cc: Xiao Guangrong <[email protected]>
---
arch/x86/kvm/mmu.c | 23 +++++++++--------------
arch/x86/kvm/paging_tmpl.h | 6 ++----
2 files changed, 11 insertions(+), 18 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 7f46e3e..ec61b22 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2119,12 +2119,8 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
if (sp->unsync && kvm_sync_page_transient(vcpu, sp))
break;
- mmu_page_add_parent_pte(vcpu, sp, parent_pte);
- if (sp->unsync_children) {
+ if (sp->unsync_children)
kvm_make_request(KVM_REQ_MMU_SYNC, vcpu);
- kvm_mmu_mark_parents_unsync(sp);
- } else if (sp->unsync)
- kvm_mmu_mark_parents_unsync(sp);
__clear_sp_write_flooding_count(sp);
trace_kvm_mmu_get_page(sp, false);
@@ -2135,8 +2131,6 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
sp = kvm_mmu_alloc_page(vcpu, direct);
- mmu_page_add_parent_pte(vcpu, sp, parent_pte);
-
sp->gfn = gfn;
sp->role = role;
hlist_add_head(&sp->hash_link,
@@ -2204,7 +2198,8 @@ static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator)
return __shadow_walk_next(iterator, *iterator->sptep);
}
-static void link_shadow_page(u64 *sptep, struct kvm_mmu_page *sp)
+static void link_shadow_page(struct kvm_vcpu *vcpu, u64 *sptep,
+ struct kvm_mmu_page *sp)
{
u64 spte;
@@ -2215,6 +2210,11 @@ static void link_shadow_page(u64 *sptep, struct kvm_mmu_page *sp)
shadow_user_mask | shadow_x_mask | shadow_accessed_mask;
mmu_spte_set(sptep, spte);
+
+ mmu_page_add_parent_pte(vcpu, sp, sptep);
+
+ if (sp->unsync_children || sp->unsync)
+ mark_unsync(sptep);
}
static void validate_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep,
@@ -2273,11 +2273,6 @@ static void kvm_mmu_page_unlink_children(struct kvm *kvm,
mmu_page_zap_pte(kvm, sp, sp->spt + i);
}
-static void kvm_mmu_put_page(struct kvm_mmu_page *sp, u64 *parent_pte)
-{
- mmu_page_remove_parent_pte(sp, parent_pte);
-}
-
static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp)
{
u64 *sptep;
@@ -2743,7 +2738,7 @@ static int __direct_map(struct kvm_vcpu *vcpu, int write, int map_writable,
iterator.level - 1,
1, ACC_ALL, iterator.sptep);
- link_shadow_page(iterator.sptep, sp);
+ link_shadow_page(vcpu, iterator.sptep, sp);
}
}
return emulate;
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 11650ea..0dcf9c8 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -598,7 +598,7 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
goto out_gpte_changed;
if (sp)
- link_shadow_page(it.sptep, sp);
+ link_shadow_page(vcpu, it.sptep, sp);
}
for (;
@@ -618,7 +618,7 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
sp = kvm_mmu_get_page(vcpu, direct_gfn, addr, it.level-1,
true, direct_access, it.sptep);
- link_shadow_page(it.sptep, sp);
+ link_shadow_page(vcpu, it.sptep, sp);
}
clear_sp_write_flooding_count(it.sptep);
@@ -629,8 +629,6 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
return emulate;
out_gpte_changed:
- if (sp)
- kvm_mmu_put_page(sp, it.sptep);
kvm_release_pfn_clean(pfn);
return 0;
}
--
2.1.0
As kvm_mmu_get_page() was changed so that every parent pointer would not
get into the sp->parent_ptes chain before the entry pointed to by it was
set properly, we can use the for_each_rmap_spte macro instead of
pte_list_walk().
Signed-off-by: Takuya Yoshikawa <[email protected]>
Cc: Xiao Guangrong <[email protected]>
---
arch/x86/kvm/mmu.c | 27 ++++++---------------------
1 file changed, 6 insertions(+), 21 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index ec61b22..204c7d4 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1007,26 +1007,6 @@ static void pte_list_remove(u64 *spte, struct kvm_rmap_head *rmap_head)
}
}
-typedef void (*pte_list_walk_fn) (u64 *spte);
-static void pte_list_walk(struct kvm_rmap_head *rmap_head, pte_list_walk_fn fn)
-{
- struct pte_list_desc *desc;
- int i;
-
- if (!rmap_head->val)
- return;
-
- if (!(rmap_head->val & 1))
- return fn((u64 *)rmap_head->val);
-
- desc = (struct pte_list_desc *)(rmap_head->val & ~1ul);
- while (desc) {
- for (i = 0; i < PTE_LIST_EXT && desc->sptes[i]; ++i)
- fn(desc->sptes[i]);
- desc = desc->more;
- }
-}
-
static struct kvm_rmap_head *__gfn_to_rmap(gfn_t gfn, int level,
struct kvm_memory_slot *slot)
{
@@ -1749,7 +1729,12 @@ static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, int direct
static void mark_unsync(u64 *spte);
static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page *sp)
{
- pte_list_walk(&sp->parent_ptes, mark_unsync);
+ u64 *sptep;
+ struct rmap_iterator iter;
+
+ for_each_rmap_spte(&sp->parent_ptes, &iter, sptep) {
+ mark_unsync(sptep);
+ }
}
static void mark_unsync(u64 *spte)
--
2.1.0
Signed-off-by: Takuya Yoshikawa <[email protected]>
---
arch/x86/kvm/mmu.c | 20 +++++++-------------
arch/x86/kvm/paging_tmpl.h | 4 ++--
2 files changed, 9 insertions(+), 15 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 204c7d4..a1a3d19 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2071,8 +2071,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
gva_t gaddr,
unsigned level,
int direct,
- unsigned access,
- u64 *parent_pte)
+ unsigned access)
{
union kvm_mmu_page_role role;
unsigned quadrant;
@@ -2720,8 +2719,7 @@ static int __direct_map(struct kvm_vcpu *vcpu, int write, int map_writable,
base_addr &= PT64_LVL_ADDR_MASK(iterator.level);
pseudo_gfn = base_addr >> PAGE_SHIFT;
sp = kvm_mmu_get_page(vcpu, pseudo_gfn, iterator.addr,
- iterator.level - 1,
- 1, ACC_ALL, iterator.sptep);
+ iterator.level - 1, 1, ACC_ALL);
link_shadow_page(vcpu, iterator.sptep, sp);
}
@@ -3078,8 +3076,7 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu)
if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
spin_lock(&vcpu->kvm->mmu_lock);
make_mmu_pages_available(vcpu);
- sp = kvm_mmu_get_page(vcpu, 0, 0, PT64_ROOT_LEVEL,
- 1, ACC_ALL, NULL);
+ sp = kvm_mmu_get_page(vcpu, 0, 0, PT64_ROOT_LEVEL, 1, ACC_ALL);
++sp->root_count;
spin_unlock(&vcpu->kvm->mmu_lock);
vcpu->arch.mmu.root_hpa = __pa(sp->spt);
@@ -3091,9 +3088,7 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu)
spin_lock(&vcpu->kvm->mmu_lock);
make_mmu_pages_available(vcpu);
sp = kvm_mmu_get_page(vcpu, i << (30 - PAGE_SHIFT),
- i << 30,
- PT32_ROOT_LEVEL, 1, ACC_ALL,
- NULL);
+ i << 30, PT32_ROOT_LEVEL, 1, ACC_ALL);
root = __pa(sp->spt);
++sp->root_count;
spin_unlock(&vcpu->kvm->mmu_lock);
@@ -3130,7 +3125,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
spin_lock(&vcpu->kvm->mmu_lock);
make_mmu_pages_available(vcpu);
sp = kvm_mmu_get_page(vcpu, root_gfn, 0, PT64_ROOT_LEVEL,
- 0, ACC_ALL, NULL);
+ 0, ACC_ALL);
root = __pa(sp->spt);
++sp->root_count;
spin_unlock(&vcpu->kvm->mmu_lock);
@@ -3163,9 +3158,8 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
}
spin_lock(&vcpu->kvm->mmu_lock);
make_mmu_pages_available(vcpu);
- sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
- PT32_ROOT_LEVEL, 0,
- ACC_ALL, NULL);
+ sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30, PT32_ROOT_LEVEL,
+ 0, ACC_ALL);
root = __pa(sp->spt);
++sp->root_count;
spin_unlock(&vcpu->kvm->mmu_lock);
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 0dcf9c8..91e939b 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -587,7 +587,7 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
if (!is_shadow_present_pte(*it.sptep)) {
table_gfn = gw->table_gfn[it.level - 2];
sp = kvm_mmu_get_page(vcpu, table_gfn, addr, it.level-1,
- false, access, it.sptep);
+ false, access);
}
/*
@@ -617,7 +617,7 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
direct_gfn = gw->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1);
sp = kvm_mmu_get_page(vcpu, direct_gfn, addr, it.level-1,
- true, direct_access, it.sptep);
+ true, direct_access);
link_shadow_page(vcpu, it.sptep, sp);
}
--
2.1.0
On 26/11/2015 13:13, Takuya Yoshikawa wrote:
> Guests worked normally in shadow paging mode (ept=0) on my test machine.
>
> Please check if the first two patches reflect what you meant correctly.
Yes, they do!
Thanks,
Paolo
> Takuya Yoshikawa (3):
> [1] KVM: x86: MMU: Move parent_pte handling from kvm_mmu_get_page() to link_shadow_page()
> [2] KVM: x86: MMU: Use for_each_rmap_spte macro instead of pte_list_walk()
> [3] KVM: x86: MMU: Remove unused parameter parent_pte from kvm_mmu_get_page()
>
> arch/x86/kvm/mmu.c | 70 +++++++++++++++-------------------------------
> arch/x86/kvm/paging_tmpl.h | 10 +++----
> 2 files changed, 26 insertions(+), 54 deletions(-)
>