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Commit 8fe681e9 authored by Gleb Natapov's avatar Gleb Natapov Committed by Avi Kivity
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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: default avatarGleb Natapov <gleb@redhat.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent f181b96d

arch/x86/include/asm/kvm_emulate.h

+3 −0
Original line number Diff line number Diff line
@@ -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,

arch/x86/kvm/emulate.c

+11 −1
Original line number Diff line number Diff line
@@ -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;

arch/x86/kvm/x86.c

+14 −14
Original line number Diff line number Diff line
@@ -3346,10 +3346,10 @@ static int kvm_write_guest_virt_system(gva_t addr, void *val, 
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 @@ static int emulator_write_emulated_onepage(unsigned long addr, 
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)