KVM: do not inject #PF in (read|write)_emulated() callbacks

Return error to x86 emulator instead of injection exception behind its back.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h
index 777240d..b7e00cb 100644 (file)
--- a/arch/x86/include/asm/kvm_emulate.h
+++ b/arch/x86/include/asm/kvm_emulate.h
@@ -94,6 +94,7 @@ struct x86_emulate_ops {
        int (*read_emulated)(unsigned long addr,
                             void *val,
                             unsigned int bytes,
+                            unsigned int *error,
                             struct kvm_vcpu *vcpu);
 
        /*
@@ -106,6 +107,7 @@ struct x86_emulate_ops {
        int (*write_emulated)(unsigned long addr,
                              const void *val,
                              unsigned int bytes,
+                             unsigned int *error,
                              struct kvm_vcpu *vcpu);
 
        /*
@@ -120,6 +122,7 @@ struct x86_emulate_ops {
                                const void *old,
                                const void *new,
                                unsigned int bytes,
+                               unsigned int *error,
                                struct kvm_vcpu *vcpu);
 
        int (*pio_in_emulated)(int size, unsigned short port, void *val,

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index d5979ec..d7a18a0 100644 (file)
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1277,6 +1277,7 @@ static int read_emulated(struct x86_emulate_ctxt *ctxt,
 {
        int rc;
        struct read_cache *mc = &ctxt->decode.mem_read;
+       u32 err;
 
        while (size) {
                int n = min(size, 8u);
@@ -1284,7 +1285,10 @@ static int read_emulated(struct x86_emulate_ctxt *ctxt,
                if (mc->pos < mc->end)
                        goto read_cached;
 
-               rc = ops->read_emulated(addr, mc->data + mc->end, n, ctxt->vcpu);
+               rc = ops->read_emulated(addr, mc->data + mc->end, n, &err,
+                                       ctxt->vcpu);
+               if (rc == X86EMUL_PROPAGATE_FAULT)
+                       kvm_inject_page_fault(ctxt->vcpu, addr, err);
                if (rc != X86EMUL_CONTINUE)
                        return rc;
                mc->end += n;
@@ -1789,6 +1793,7 @@ static inline int writeback(struct x86_emulate_ctxt *ctxt,
 {
        int rc;
        struct decode_cache *c = &ctxt->decode;
+       u32 err;
 
        switch (c->dst.type) {
        case OP_REG:
@@ -1817,13 +1822,18 @@ static inline int writeback(struct x86_emulate_ctxt *ctxt,
                                        &c->dst.orig_val,
                                        &c->dst.val,
                                        c->dst.bytes,
+                                       &err,
                                        ctxt->vcpu);
                else
                        rc = ops->write_emulated(
                                        (unsigned long)c->dst.ptr,
                                        &c->dst.val,
                                        c->dst.bytes,
+                                       &err,
                                        ctxt->vcpu);
+               if (rc == X86EMUL_PROPAGATE_FAULT)
+                       kvm_inject_page_fault(ctxt->vcpu,
+                                             (unsigned long)c->dst.ptr, err);
                if (rc != X86EMUL_CONTINUE)
                        return rc;
                break;

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 15a4b75..51402d8 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3346,10 +3346,10 @@ out:
 static int emulator_read_emulated(unsigned long addr,
                                  void *val,
                                  unsigned int bytes,
+                                 unsigned int *error_code,
                                  struct kvm_vcpu *vcpu)
 {
        gpa_t                 gpa;
-       u32 error_code;
 
        if (vcpu->mmio_read_completed) {
                memcpy(val, vcpu->mmio_data, bytes);
@@ -3359,12 +3359,10 @@ static int emulator_read_emulated(unsigned long addr,
                return X86EMUL_CONTINUE;
        }
 
-       gpa = kvm_mmu_gva_to_gpa_read(vcpu, addr, &error_code);
+       gpa = kvm_mmu_gva_to_gpa_read(vcpu, addr, error_code);
 
-       if (gpa == UNMAPPED_GVA) {
-               kvm_inject_page_fault(vcpu, addr, error_code);
+       if (gpa == UNMAPPED_GVA)
                return X86EMUL_PROPAGATE_FAULT;
-       }
 
        /* For APIC access vmexit */
        if ((gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE)
@@ -3409,17 +3407,15 @@ int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
 static int emulator_write_emulated_onepage(unsigned long addr,
                                           const void *val,
                                           unsigned int bytes,
+                                          unsigned int *error_code,
                                           struct kvm_vcpu *vcpu)
 {
        gpa_t                 gpa;
-       u32 error_code;
 
-       gpa = kvm_mmu_gva_to_gpa_write(vcpu, addr, &error_code);
+       gpa = kvm_mmu_gva_to_gpa_write(vcpu, addr, error_code);
 
-       if (gpa == UNMAPPED_GVA) {
-               kvm_inject_page_fault(vcpu, addr, error_code);
+       if (gpa == UNMAPPED_GVA)
                return X86EMUL_PROPAGATE_FAULT;
-       }
 
        /* For APIC access vmexit */
        if ((gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE)
@@ -3449,6 +3445,7 @@ mmio:
 int emulator_write_emulated(unsigned long addr,
                            const void *val,
                            unsigned int bytes,
+                           unsigned int *error_code,
                            struct kvm_vcpu *vcpu)
 {
        /* Crossing a page boundary? */
@@ -3456,14 +3453,16 @@ int emulator_write_emulated(unsigned long addr,
                int rc, now;
 
                now = -addr & ~PAGE_MASK;
-               rc = emulator_write_emulated_onepage(addr, val, now, vcpu);
+               rc = emulator_write_emulated_onepage(addr, val, now, error_code,
+                                                    vcpu);
                if (rc != X86EMUL_CONTINUE)
                        return rc;
                addr += now;
                val += now;
                bytes -= now;
        }
-       return emulator_write_emulated_onepage(addr, val, bytes, vcpu);
+       return emulator_write_emulated_onepage(addr, val, bytes, error_code,
+                                              vcpu);
 }
 
 #define CMPXCHG_TYPE(t, ptr, old, new) \
@@ -3480,6 +3479,7 @@ static int emulator_cmpxchg_emulated(unsigned long addr,
                                     const void *old,
                                     const void *new,
                                     unsigned int bytes,
+                                    unsigned int *error_code,
                                     struct kvm_vcpu *vcpu)
 {
        gpa_t gpa;
@@ -3533,7 +3533,7 @@ static int emulator_cmpxchg_emulated(unsigned long addr,
 emul_write:
        printk_once(KERN_WARNING "kvm: emulating exchange as write\n");
 
-       return emulator_write_emulated(addr, new, bytes, vcpu);
+       return emulator_write_emulated(addr, new, bytes, error_code, vcpu);
 }
 
 static int kernel_pio(struct kvm_vcpu *vcpu, void *pd)
@@ -4293,7 +4293,7 @@ int kvm_fix_hypercall(struct kvm_vcpu *vcpu)
 
        kvm_x86_ops->patch_hypercall(vcpu, instruction);
 
-       return emulator_write_emulated(rip, instruction, 3, vcpu);
+       return emulator_write_emulated(rip, instruction, 3, NULL, vcpu);
 }
 
 void realmode_lgdt(struct kvm_vcpu *vcpu, u16 limit, unsigned long base)