Introduce it to split the code of adjusting pte_access from the large
function of set_spte
Signed-off-by: Xiao Guangrong <xiaoguangr...@linux.vnet.ibm.com>
---
arch/x86/kvm/mmu.c | 63 +++++++++++++++++++++++++++++++++-------------------
1 files changed, 40 insertions(+), 23 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index af8bcb2..43b7e0c 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2324,25 +2324,18 @@ static int mmu_need_write_protect(struct kvm_vcpu
*vcpu, gfn_t gfn,
return 0;
}
-static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
- unsigned pte_access, int level,
- gfn_t gfn, pfn_t pfn, bool speculative,
- bool can_unsync, bool host_writable)
+/*
+ * Return -1 if a race condition is detected, 1 if @gfn need to be
+ * write-protected, otherwise 0 is returned.
+ */
+static int vcpu_adjust_access(struct kvm_vcpu *vcpu, u64 *sptep,
+ unsigned *pte_access, int level, gfn_t gfn,
+ bool can_unsync, bool host_writable)
{
- u64 spte;
- int ret = 0;
-
- if (set_mmio_spte(sptep, gfn, pfn, pte_access))
- return 0;
+ if (!host_writable)
+ *pte_access &= ~ACC_WRITE_MASK;
- spte = PT_PRESENT_MASK;
-
- if (host_writable)
- spte |= SPTE_HOST_WRITEABLE;
- else
- pte_access &= ~ACC_WRITE_MASK;
-
- if (pte_access & ACC_WRITE_MASK) {
+ if (*pte_access & ACC_WRITE_MASK) {
/*
* Other vcpu creates new sp in the window between
* mapping_level() and acquiring mmu-lock. We can
@@ -2351,7 +2344,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
*/
if (level > PT_PAGE_TABLE_LEVEL &&
has_wrprotected_page(vcpu->kvm, gfn, level))
- goto done;
+ return -1;
/*
* Optimization: for pte sync, if spte was writable the hash
@@ -2360,17 +2353,41 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
* Same reasoning can be applied to dirty page accounting.
*/
if (!can_unsync && is_writable_pte(*sptep))
- goto out_access_adjust;
+ return 0;
if (mmu_need_write_protect(vcpu, gfn, can_unsync)) {
pgprintk("%s: found shadow page for %llx, marking ro\n",
__func__, gfn);
- ret = 1;
- pte_access &= ~ACC_WRITE_MASK;
+
+ *pte_access &= ~ACC_WRITE_MASK;
+ return 1;
}
}
-out_access_adjust:
+ return 0;
+}
+
+static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
+ unsigned pte_access, int level,
+ gfn_t gfn, pfn_t pfn, bool speculative,
+ bool can_unsync, bool host_writable)
+{
+ u64 spte;
+ int ret;
+
+ if (set_mmio_spte(sptep, gfn, pfn, pte_access))
+ return 0;
+
+ ret = vcpu_adjust_access(vcpu, sptep, &pte_access, level, gfn,
+ can_unsync, host_writable);
+ if (ret < 0)
+ return 0;
+
+ spte = PT_PRESENT_MASK;
+
+ if (host_writable)
+ spte |= SPTE_HOST_WRITEABLE;
+
if (!speculative)
spte |= shadow_accessed_mask;
@@ -2399,7 +2416,7 @@ out_access_adjust:
if (mmu_spte_update(sptep, spte))
kvm_flush_remote_tlbs(vcpu->kvm);
-done:
+
return ret;
}
--
1.7.7.6
--
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