mmu_set_spte()'s code is based on the assumption that the emulate
parameter has a valid pointer value if set_spte() returns true and
write_fault is not zero. In other cases, emulate may be NULL, so a
NULL-check is needed.
Stop passing emulate pointer and make mmu_set_spte() return the emulate
value instead to clean up this complex interface. Prefetch functions
can just throw away the return value.
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya...@lab.ntt.co.jp>
---
arch/x86/kvm/mmu.c | 27 ++++++++++++++-------------
arch/x86/kvm/paging_tmpl.h | 10 +++++-----
2 files changed, 19 insertions(+), 18 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 9832bc9..74c120c 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2564,13 +2564,13 @@ done:
return ret;
}
-static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
- unsigned pte_access, int write_fault, int *emulate,
- int level, gfn_t gfn, pfn_t pfn, bool speculative,
- bool host_writable)
+static bool mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, unsigned
pte_access,
+ int write_fault, int level, gfn_t gfn, pfn_t pfn,
+ bool speculative, bool host_writable)
{
int was_rmapped = 0;
int rmap_count;
+ bool emulate = false;
pgprintk("%s: spte %llx write_fault %d gfn %llx\n", __func__,
*sptep, write_fault, gfn);
@@ -2600,12 +2600,12 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64
*sptep,
if (set_spte(vcpu, sptep, pte_access, level, gfn, pfn, speculative,
true, host_writable)) {
if (write_fault)
- *emulate = 1;
+ emulate = true;
kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
}
- if (unlikely(is_mmio_spte(*sptep) && emulate))
- *emulate = 1;
+ if (unlikely(is_mmio_spte(*sptep)))
+ emulate = true;
pgprintk("%s: setting spte %llx\n", __func__, *sptep);
pgprintk("instantiating %s PTE (%s) at %llx (%llx) addr %p\n",
@@ -2624,6 +2624,8 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64
*sptep,
}
kvm_release_pfn_clean(pfn);
+
+ return emulate;
}
static pfn_t pte_prefetch_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn,
@@ -2658,9 +2660,8 @@ 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, access, 0, NULL,
- sp->role.level, gfn, page_to_pfn(pages[i]),
- true, true);
+ mmu_set_spte(vcpu, start, access, 0, sp->role.level, gfn,
+ page_to_pfn(pages[i]), true, true);
return 0;
}
@@ -2721,9 +2722,9 @@ static int __direct_map(struct kvm_vcpu *vcpu, int write,
int map_writable,
for_each_shadow_entry(vcpu, (u64)gfn << PAGE_SHIFT, iterator) {
if (iterator.level == level) {
- mmu_set_spte(vcpu, iterator.sptep, ACC_ALL,
- write, &emulate, level, gfn, pfn,
- prefault, map_writable);
+ emulate = mmu_set_spte(vcpu, iterator.sptep, ACC_ALL,
+ write, 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 d8fdc5c..11650ea 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -475,8 +475,8 @@ 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, pte_access, 0, NULL, PT_PAGE_TABLE_LEVEL,
- gfn, pfn, true, true);
+ mmu_set_spte(vcpu, spte, pte_access, 0, PT_PAGE_TABLE_LEVEL, gfn, pfn,
+ true, true);
return true;
}
@@ -556,7 +556,7 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
struct kvm_mmu_page *sp = NULL;
struct kvm_shadow_walk_iterator it;
unsigned direct_access, access = gw->pt_access;
- int top_level, emulate = 0;
+ int top_level, emulate;
direct_access = gw->pte_access;
@@ -622,8 +622,8 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
}
clear_sp_write_flooding_count(it.sptep);
- mmu_set_spte(vcpu, it.sptep, gw->pte_access, write_fault, &emulate,
- it.level, gw->gfn, pfn, prefault, map_writable);
+ emulate = mmu_set_spte(vcpu, it.sptep, gw->pte_access, write_fault,
+ it.level, gw->gfn, pfn, prefault, map_writable);
FNAME(pte_prefetch)(vcpu, gw, it.sptep);
return emulate;
--
2.1.0
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