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Commit 27e6fb5d authored by Nadav Amit's avatar Nadav Amit Committed by Paolo Bonzini
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KVM: vmx: vmx instructions handling does not consider cs.l 



VMX instructions use 32-bit operands in 32-bit mode, and 64-bit operands in
64-bit mode.  The current implementation is broken since it does not use the
register operands correctly, and always uses 64-bit for reads and writes.
Moreover, write to memory in vmwrite only considers long-mode, so it ignores
cs.l. This patch fixes this behavior.

Signed-off-by: default avatarNadav Amit <namit@cs.technion.ac.il>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 1e32c079

arch/x86/kvm/vmx.c

+6 −6
Original line number Original line Diff line number Diff line
@@ -6403,7 +6403,7 @@ static int handle_vmread(struct kvm_vcpu *vcpu) 
		return 1;

		return 1;





	/* Decode instruction info and find the field to read */

	/* Decode instruction info and find the field to read */

	field = kvm_register_read(vcpu, (((vmx_instruction_info) >> 28) & 0xf));

	field = kvm_register_readl(vcpu, (((vmx_instruction_info) >> 28) & 0xf));

	/* Read the field, zero-extended to a u64 field_value */

	/* Read the field, zero-extended to a u64 field_value */

	if (!vmcs12_read_any(vcpu, field, &field_value)) {

	if (!vmcs12_read_any(vcpu, field, &field_value)) {

		nested_vmx_failValid(vcpu, VMXERR_UNSUPPORTED_VMCS_COMPONENT);

		nested_vmx_failValid(vcpu, VMXERR_UNSUPPORTED_VMCS_COMPONENT);
@@ -6416,7 +6416,7 @@ static int handle_vmread(struct kvm_vcpu *vcpu) 
	 * on the guest's mode (32 or 64 bit), not on the given field's length.

	 * on the guest's mode (32 or 64 bit), not on the given field's length.

	 */

	 */

	if (vmx_instruction_info & (1u << 10)) {

	if (vmx_instruction_info & (1u << 10)) {

		kvm_register_write(vcpu, (((vmx_instruction_info) >> 3) & 0xf),

		kvm_register_writel(vcpu, (((vmx_instruction_info) >> 3) & 0xf),

			field_value);

			field_value);

	} else {

	} else {

		if (get_vmx_mem_address(vcpu, exit_qualification,

		if (get_vmx_mem_address(vcpu, exit_qualification,
@@ -6453,21 +6453,21 @@ static int handle_vmwrite(struct kvm_vcpu *vcpu) 
		return 1;

		return 1;





	if (vmx_instruction_info & (1u << 10))

	if (vmx_instruction_info & (1u << 10))

		field_value = kvm_register_read(vcpu,

		field_value = kvm_register_readl(vcpu,

			(((vmx_instruction_info) >> 3) & 0xf));

			(((vmx_instruction_info) >> 3) & 0xf));

	else {

	else {

		if (get_vmx_mem_address(vcpu, exit_qualification,

		if (get_vmx_mem_address(vcpu, exit_qualification,

				vmx_instruction_info, &gva))

				vmx_instruction_info, &gva))

			return 1;

			return 1;

		if (kvm_read_guest_virt(&vcpu->arch.emulate_ctxt, gva,

		if (kvm_read_guest_virt(&vcpu->arch.emulate_ctxt, gva,

			   &field_value, (is_long_mode(vcpu) ? 8 : 4), &e)) {

			   &field_value, (is_64_bit_mode(vcpu) ? 8 : 4), &e)) {

			kvm_inject_page_fault(vcpu, &e);

			kvm_inject_page_fault(vcpu, &e);

			return 1;

			return 1;

		}

		}

	}

	}









	field = kvm_register_read(vcpu, (((vmx_instruction_info) >> 28) & 0xf));

	field = kvm_register_readl(vcpu, (((vmx_instruction_info) >> 28) & 0xf));

	if (vmcs_field_readonly(field)) {

	if (vmcs_field_readonly(field)) {

		nested_vmx_failValid(vcpu,

		nested_vmx_failValid(vcpu,

			VMXERR_VMWRITE_READ_ONLY_VMCS_COMPONENT);

			VMXERR_VMWRITE_READ_ONLY_VMCS_COMPONENT);
@@ -6590,7 +6590,7 @@ static int handle_invept(struct kvm_vcpu *vcpu) 
	}

	}





	vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);

	vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);

	type = kvm_register_read(vcpu, (vmx_instruction_info >> 28) & 0xf);

	type = kvm_register_readl(vcpu, (vmx_instruction_info >> 28) & 0xf);





	types = (nested_vmx_ept_caps >> VMX_EPT_EXTENT_SHIFT) & 6;

	types = (nested_vmx_ept_caps >> VMX_EPT_EXTENT_SHIFT) & 6;

arch/x86/kvm/x86.h

+9 −0
Original line number Original line Diff line number Diff line
@@ -126,6 +126,15 @@ static inline unsigned long kvm_register_readl(struct kvm_vcpu *vcpu, 
	return is_64_bit_mode(vcpu) ? val : (u32)val;

	return is_64_bit_mode(vcpu) ? val : (u32)val;

}

}





static inline void kvm_register_writel(struct kvm_vcpu *vcpu,

				       enum kvm_reg reg,

				       unsigned long val)

{

	if (!is_64_bit_mode(vcpu))

		val = (u32)val;

	return kvm_register_write(vcpu, reg, val);

}



void kvm_before_handle_nmi(struct kvm_vcpu *vcpu);

void kvm_before_handle_nmi(struct kvm_vcpu *vcpu);

void kvm_after_handle_nmi(struct kvm_vcpu *vcpu);

void kvm_after_handle_nmi(struct kvm_vcpu *vcpu);

int kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq, int inc_eip);

int kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq, int inc_eip);