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Subject[PATCH v2 1/5] KVM: MMU: move adjusting pte access for softmmu to FNAME(page_fault)
Then, no mmu specified code exists in the common function and drop two
parameters in set_spte

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
---
arch/x86/kvm/mmu.c | 47 ++++++++++++-------------------------------
arch/x86/kvm/paging_tmpl.h | 25 ++++++++++++++++++----
2 files changed, 33 insertions(+), 39 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 01d7c2a..2a3c890 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2342,8 +2342,7 @@ static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
}

static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
- unsigned pte_access, int user_fault,
- int write_fault, int level,
+ unsigned pte_access, int level,
gfn_t gfn, pfn_t pfn, bool speculative,
bool can_unsync, bool host_writable)
{
@@ -2378,9 +2377,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,

spte |= (u64)pfn << PAGE_SHIFT;

- if ((pte_access & ACC_WRITE_MASK)
- || (!vcpu->arch.mmu.direct_map && write_fault
- && !is_write_protection(vcpu) && !user_fault)) {
+ if (pte_access & ACC_WRITE_MASK) {

/*
* There are two cases:
@@ -2399,19 +2396,6 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,

spte |= PT_WRITABLE_MASK | SPTE_MMU_WRITEABLE;

- if (!vcpu->arch.mmu.direct_map
- && !(pte_access & ACC_WRITE_MASK)) {
- spte &= ~PT_USER_MASK;
- /*
- * If we converted a user page to a kernel page,
- * so that the kernel can write to it when cr0.wp=0,
- * then we should prevent the kernel from executing it
- * if SMEP is enabled.
- */
- if (kvm_read_cr4_bits(vcpu, X86_CR4_SMEP))
- spte |= PT64_NX_MASK;
- }
-
/*
* Optimization: for pte sync, if spte was writable the hash
* lookup is unnecessary (and expensive). Write protection
@@ -2442,18 +2426,15 @@ done:

static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
unsigned pt_access, unsigned pte_access,
- int user_fault, int write_fault,
- int *emulate, int level, gfn_t gfn,
- pfn_t pfn, bool speculative,
- bool host_writable)
+ int write_fault, int *emulate, int level, gfn_t gfn,
+ pfn_t pfn, bool speculative, bool host_writable)
{
int was_rmapped = 0;
int rmap_count;

- pgprintk("%s: spte %llx access %x write_fault %d"
- " user_fault %d gfn %llx\n",
+ pgprintk("%s: spte %llx access %x write_fault %d gfn %llx\n",
__func__, *sptep, pt_access,
- write_fault, user_fault, gfn);
+ write_fault, gfn);

if (is_rmap_spte(*sptep)) {
/*
@@ -2477,9 +2458,8 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
was_rmapped = 1;
}

- if (set_spte(vcpu, sptep, pte_access, user_fault, write_fault,
- level, gfn, pfn, speculative, true,
- host_writable)) {
+ if (set_spte(vcpu, sptep, pte_access, level, gfn, pfn, speculative,
+ true, host_writable)) {
if (write_fault)
*emulate = 1;
kvm_mmu_flush_tlb(vcpu);
@@ -2571,10 +2551,9 @@ static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu,
return -1;

for (i = 0; i < ret; i++, gfn++, start++)
- mmu_set_spte(vcpu, start, ACC_ALL,
- access, 0, 0, NULL,
- sp->role.level, gfn,
- page_to_pfn(pages[i]), true, true);
+ mmu_set_spte(vcpu, start, ACC_ALL, access, 0, NULL,
+ sp->role.level, gfn, page_to_pfn(pages[i]),
+ true, true);

return 0;
}
@@ -2636,8 +2615,8 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write,
unsigned pte_access = ACC_ALL;

mmu_set_spte(vcpu, iterator.sptep, ACC_ALL, pte_access,
- 0, write, &emulate,
- level, gfn, pfn, prefault, map_writable);
+ write, &emulate, level, gfn, pfn,
+ prefault, map_writable);
direct_pte_prefetch(vcpu, iterator.sptep);
++vcpu->stat.pf_fixed;
break;
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 891eb6d..ec481e9 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -330,7 +330,7 @@ FNAME(prefetch_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
* we call mmu_set_spte() with host_writable = true because
* pte_prefetch_gfn_to_pfn always gets a writable pfn.
*/
- mmu_set_spte(vcpu, spte, sp->role.access, pte_access, 0, 0,
+ mmu_set_spte(vcpu, spte, sp->role.access, pte_access, 0,
NULL, PT_PAGE_TABLE_LEVEL, gfn, pfn, true, true);

return true;
@@ -405,7 +405,7 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw,
*/
static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
struct guest_walker *gw,
- int user_fault, int write_fault, int hlevel,
+ int write_fault, int hlevel,
pfn_t pfn, bool map_writable, bool prefault)
{
struct kvm_mmu_page *sp = NULL;
@@ -478,7 +478,7 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,

clear_sp_write_flooding_count(it.sptep);
mmu_set_spte(vcpu, it.sptep, access, gw->pte_access,
- user_fault, write_fault, &emulate, it.level,
+ write_fault, &emulate, it.level,
gw->gfn, pfn, prefault, map_writable);
FNAME(pte_prefetch)(vcpu, gw, it.sptep);

@@ -544,6 +544,21 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code,
return 0;
}

+ if (write_fault && !(walker.pte_access & ACC_WRITE_MASK) &&
+ !is_write_protection(vcpu) && !user_fault) {
+ walker.pte_access |= ACC_WRITE_MASK;
+ walker.pte_access &= ~ACC_USER_MASK;
+
+ /*
+ * If we converted a user page to a kernel page,
+ * so that the kernel can write to it when cr0.wp=0,
+ * then we should prevent the kernel from executing it
+ * if SMEP is enabled.
+ */
+ if (kvm_read_cr4_bits(vcpu, X86_CR4_SMEP))
+ walker.pte_access &= ~ACC_EXEC_MASK;
+ }
+
if (walker.level >= PT_DIRECTORY_LEVEL)
force_pt_level = mapping_level_dirty_bitmap(vcpu, walker.gfn);
else
@@ -572,7 +587,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code,
kvm_mmu_free_some_pages(vcpu);
if (!force_pt_level)
transparent_hugepage_adjust(vcpu, &walker.gfn, &pfn, &level);
- r = FNAME(fetch)(vcpu, addr, &walker, user_fault, write_fault,
+ r = FNAME(fetch)(vcpu, addr, &walker, write_fault,
level, pfn, map_writable, prefault);
++vcpu->stat.pf_fixed;
kvm_mmu_audit(vcpu, AUDIT_POST_PAGE_FAULT);
@@ -747,7 +762,7 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)

host_writable = sp->spt[i] & SPTE_HOST_WRITEABLE;

- set_spte(vcpu, &sp->spt[i], pte_access, 0, 0,
+ set_spte(vcpu, &sp->spt[i], pte_access,
PT_PAGE_TABLE_LEVEL, gfn,
spte_to_pfn(sp->spt[i]), true, false,
host_writable);
--
1.7.7.6


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