KVM: do not treat noslot pfn as a error pfn

This patch filters noslot pfn out from error pfns based on Marcelo comment:
noslot pfn is not a error pfn

After this patch,
- is_noslot_pfn indicates that the gfn is not in slot
- is_error_pfn indicates that the gfn is in slot but the error is occurred
  when translate the gfn to pfn
- is_error_noslot_pfn indicates that the pfn either it is error pfns or it
  is noslot pfn
And is_invalid_pfn can be removed, it makes the code more clean

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

diff --git a/arch/powerpc/kvm/book3s_32_mmu_host.c b/arch/powerpc/kvm/book3s_32_mmu_host.c
index d1107a9b5d130d08dc8f4e20ec6e8f697a3c285e..00e619bf608ef124c6b348e236afebff258089b5 100644 (file)
--- a/arch/powerpc/kvm/book3s_32_mmu_host.c
+++ b/arch/powerpc/kvm/book3s_32_mmu_host.c
@@ -155,7 +155,7 @@ int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte)
 
        /* Get host physical address for gpa */
        hpaddr = kvmppc_gfn_to_pfn(vcpu, orig_pte->raddr >> PAGE_SHIFT);
-       if (is_error_pfn(hpaddr)) {
+       if (is_error_noslot_pfn(hpaddr)) {
                printk(KERN_INFO "Couldn't get guest page for gfn %lx!\n",
                                 orig_pte->eaddr);
                r = -EINVAL;

diff --git a/arch/powerpc/kvm/book3s_64_mmu_host.c b/arch/powerpc/kvm/book3s_64_mmu_host.c
index d0205a545a81913d1a0698884ee9d6a69ae75075..ead58e3172945d81e863ba937cc1d88b93922558 100644 (file)
--- a/arch/powerpc/kvm/book3s_64_mmu_host.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_host.c
@@ -93,7 +93,7 @@ int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte)
 
        /* Get host physical address for gpa */
        hpaddr = kvmppc_gfn_to_pfn(vcpu, orig_pte->raddr >> PAGE_SHIFT);
-       if (is_error_pfn(hpaddr)) {
+       if (is_error_noslot_pfn(hpaddr)) {
                printk(KERN_INFO "Couldn't get guest page for gfn %lx!\n", orig_pte->eaddr);
                r = -EINVAL;
                goto out;

diff --git a/arch/powerpc/kvm/e500_tlb.c b/arch/powerpc/kvm/e500_tlb.c
index c73389477d177226c5f6f3009868bb77b72cd50a..6305ee692ef76ff0a58d6f0f944ea4adf84d86ae 100644 (file)
--- a/arch/powerpc/kvm/e500_tlb.c
+++ b/arch/powerpc/kvm/e500_tlb.c
@@ -524,7 +524,7 @@ static inline void kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500,
        if (likely(!pfnmap)) {
                unsigned long tsize_pages = 1 << (tsize + 10 - PAGE_SHIFT);
                pfn = gfn_to_pfn_memslot(slot, gfn);
-               if (is_error_pfn(pfn)) {
+               if (is_error_noslot_pfn(pfn)) {
                        printk(KERN_ERR "Couldn't get real page for gfn %lx!\n",
                                        (long)gfn);
                        return;

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index aabb1289ff04c906b1d3dfa442185f7c3dc7d189..b875a9ed9b8e3d75dc92e2889b58ed12926c3906 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2699,7 +2699,7 @@ static void transparent_hugepage_adjust(struct kvm_vcpu *vcpu,
         * PT_PAGE_TABLE_LEVEL and there would be no adjustment done
         * here.
         */
-       if (!is_error_pfn(pfn) && !kvm_is_mmio_pfn(pfn) &&
+       if (!is_error_noslot_pfn(pfn) && !kvm_is_mmio_pfn(pfn) &&
            level == PT_PAGE_TABLE_LEVEL &&
            PageTransCompound(pfn_to_page(pfn)) &&
            !has_wrprotected_page(vcpu->kvm, gfn, PT_DIRECTORY_LEVEL)) {
@@ -2733,7 +2733,7 @@ static bool handle_abnormal_pfn(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn,
        bool ret = true;
 
        /* The pfn is invalid, report the error! */
-       if (unlikely(is_invalid_pfn(pfn))) {
+       if (unlikely(is_error_pfn(pfn))) {
                *ret_val = kvm_handle_bad_page(vcpu, gfn, pfn);
                goto exit;
        }

diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index d17decaf1db9fafafff86079d072dcb2218c91dd..891eb6d93b8b32b2d4bb7f85c45702d314d14615 100644 (file)
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -323,7 +323,7 @@ FNAME(prefetch_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
        protect_clean_gpte(&pte_access, gpte);
        pfn = pte_prefetch_gfn_to_pfn(vcpu, gfn,
                        no_dirty_log && (pte_access & ACC_WRITE_MASK));
-       if (is_invalid_pfn(pfn))
+       if (is_error_pfn(pfn))
                return false;
 
        /*

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 6e5f069bee30ce54fe1e16b46b21f90af8672fe7..49fa1f0e59bd8311497fa6554115f6a58fefebf7 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4504,7 +4504,7 @@ static bool reexecute_instruction(struct kvm_vcpu *vcpu, gva_t gva)
         * instruction -> ...
         */
        pfn = gfn_to_pfn(vcpu->kvm, gpa_to_gfn(gpa));
-       if (!is_error_pfn(pfn)) {
+       if (!is_error_noslot_pfn(pfn)) {
                kvm_release_pfn_clean(pfn);
                return true;
        }

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 82e2c783a21e5b0cbe7bc4090e1c709f6a986c23..99a47627e046c84fb81788137c0e9b42d1174ea5 100644 (file)
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -58,28 +58,40 @@
 
 /*
  * For the normal pfn, the highest 12 bits should be zero,
- * so we can mask these bits to indicate the error.
+ * so we can mask bit 62 ~ bit 52  to indicate the error pfn,
+ * mask bit 63 to indicate the noslot pfn.
  */
-#define KVM_PFN_ERR_MASK       (0xfffULL << 52)
+#define KVM_PFN_ERR_MASK       (0x7ffULL << 52)
+#define KVM_PFN_ERR_NOSLOT_MASK        (0xfffULL << 52)
+#define KVM_PFN_NOSLOT         (0x1ULL << 63)
 
 #define KVM_PFN_ERR_FAULT      (KVM_PFN_ERR_MASK)
 #define KVM_PFN_ERR_HWPOISON   (KVM_PFN_ERR_MASK + 1)
-#define KVM_PFN_ERR_BAD                (KVM_PFN_ERR_MASK + 2)
-#define KVM_PFN_ERR_RO_FAULT   (KVM_PFN_ERR_MASK + 3)
+#define KVM_PFN_ERR_RO_FAULT   (KVM_PFN_ERR_MASK + 2)
 
+/*
+ * error pfns indicate that the gfn is in slot but faild to
+ * translate it to pfn on host.
+ */
 static inline bool is_error_pfn(pfn_t pfn)
 {
        return !!(pfn & KVM_PFN_ERR_MASK);
 }
 
-static inline bool is_noslot_pfn(pfn_t pfn)
+/*
+ * error_noslot pfns indicate that the gfn can not be
+ * translated to pfn - it is not in slot or failed to
+ * translate it to pfn.
+ */
+static inline bool is_error_noslot_pfn(pfn_t pfn)
 {
-       return pfn == KVM_PFN_ERR_BAD;
+       return !!(pfn & KVM_PFN_ERR_NOSLOT_MASK);
 }
 
-static inline bool is_invalid_pfn(pfn_t pfn)
+/* noslot pfn indicates that the gfn is not in slot. */
+static inline bool is_noslot_pfn(pfn_t pfn)
 {
-       return !is_noslot_pfn(pfn) && is_error_pfn(pfn);
+       return pfn == KVM_PFN_NOSLOT;
 }
 
 #define KVM_HVA_ERR_BAD                (PAGE_OFFSET)

diff --git a/virt/kvm/iommu.c b/virt/kvm/iommu.c
index 18e1e30019e3f573a8cd3540bc781b5648a239d4..4a340cb230134bd7fb15b62545ff8b5245ecbfa2 100644 (file)
--- a/virt/kvm/iommu.c
+++ b/virt/kvm/iommu.c
@@ -52,7 +52,7 @@ static pfn_t kvm_pin_pages(struct kvm_memory_slot *slot, gfn_t gfn,
        end_gfn = gfn + (size >> PAGE_SHIFT);
        gfn    += 1;
 
-       if (is_error_pfn(pfn))
+       if (is_error_noslot_pfn(pfn))
                return pfn;
 
        while (gfn < end_gfn)
@@ -106,7 +106,7 @@ int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot)
                 * important because we unmap and unpin in 4kb steps later.
                 */
                pfn = kvm_pin_pages(slot, gfn, page_size);
-               if (is_error_pfn(pfn)) {
+               if (is_error_noslot_pfn(pfn)) {
                        gfn += 1;
                        continue;
                }

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index be70035fd42a14edad4c24ae411c4b9d3fdf396c..2fb73191801f60694c10cf1feda9831781723146 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1208,7 +1208,7 @@ __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn, bool atomic,
                return KVM_PFN_ERR_RO_FAULT;
 
        if (kvm_is_error_hva(addr))
-               return KVM_PFN_ERR_BAD;
+               return KVM_PFN_NOSLOT;
 
        /* Do not map writable pfn in the readonly memslot. */
        if (writable && memslot_is_readonly(slot)) {
@@ -1290,7 +1290,7 @@ EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic);
 
 static struct page *kvm_pfn_to_page(pfn_t pfn)
 {
-       if (is_error_pfn(pfn))
+       if (is_error_noslot_pfn(pfn))
                return KVM_ERR_PTR_BAD_PAGE;
 
        if (kvm_is_mmio_pfn(pfn)) {
@@ -1322,7 +1322,7 @@ EXPORT_SYMBOL_GPL(kvm_release_page_clean);
 
 void kvm_release_pfn_clean(pfn_t pfn)
 {
-       if (!is_error_pfn(pfn) && !kvm_is_mmio_pfn(pfn))
+       if (!is_error_noslot_pfn(pfn) && !kvm_is_mmio_pfn(pfn))
                put_page(pfn_to_page(pfn));
 }
 EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);