On 06/13/2010 03:26 PM, Nadav Har'El wrote:
This patch includes a couple of utility functions for extracting pointer
operands of VMX instructions issued by L1 (a guest hypervisor), and
translating guest-given vmcs12 virtual addresses to guest-physical addresses.
+/*
+ * Decode the memory-address operand of a vmx instruction, according to the
+ * Intel spec.
+ */
+#define VMX_OPERAND_SCALING(vii) ((vii)& 3)
+#define VMX_OPERAND_ADDR_SIZE(vii) (((vii)>> 7)& 7)
+#define VMX_OPERAND_IS_REG(vii) ((vii)& (1u<< 10))
+#define VMX_OPERAND_SEG_REG(vii) (((vii)>> 15)& 7)
+#define VMX_OPERAND_INDEX_REG(vii) (((vii)>> 18)& 0xf)
+#define VMX_OPERAND_INDEX_INVALID(vii) ((vii)& (1u<< 22))
+#define VMX_OPERAND_BASE_REG(vii) (((vii)>> 23)& 0xf)
+#define VMX_OPERAND_BASE_INVALID(vii) ((vii)& (1u<< 27))
+#define VMX_OPERAND_REG(vii) (((vii)>> 3)& 0xf)
+#define VMX_OPERAND_REG2(vii) (((vii)>> 28)& 0xf)
+static gva_t get_vmx_mem_address(struct kvm_vcpu *vcpu,
+ unsigned long exit_qualification,
+ u32 vmx_instruction_info)
+{
+ int scaling = VMX_OPERAND_SCALING(vmx_instruction_info);
+ int addr_size = VMX_OPERAND_ADDR_SIZE(vmx_instruction_info);
+ bool is_reg = VMX_OPERAND_IS_REG(vmx_instruction_info);
+ int seg_reg = VMX_OPERAND_SEG_REG(vmx_instruction_info);
+ int index_reg = VMX_OPERAND_SEG_REG(vmx_instruction_info);
+ bool index_is_valid = !VMX_OPERAND_INDEX_INVALID(vmx_instruction_info);
+ int base_reg = VMX_OPERAND_BASE_REG(vmx_instruction_info);
+ bool base_is_valid = !VMX_OPERAND_BASE_INVALID(vmx_instruction_info);
Since those defines are used just ones, you can fold them into their
uses. It doesn't add much to repeat the variable name.
+ gva_t addr;
+
+ if (is_reg) {
+ kvm_queue_exception(vcpu, UD_VECTOR);
+ return 0;
+ }
+
+ switch (addr_size) {
+ case 1: /* 32 bit. high bits are undefined according to the spec: */
+ exit_qualification&= 0xffffffff;
+ break;
+ case 2: /* 64 bit */
+ break;
+ default: /* addr_size=0 means 16 bit */
+ return 0;
+ }
+
+ /* Addr = segment_base + offset */
+ /* offfset = Base + [Index * Scale] + Displacement */
+ addr = vmx_get_segment_base(vcpu, seg_reg);
+ if (base_is_valid)
+ addr += kvm_register_read(vcpu, base_reg);
+ if (index_is_valid)
+ addr += kvm_register_read(vcpu, index_reg)<<scaling;
+ addr += exit_qualification; /* holds the displacement */
Do we need a segment limit and access rights check?
+
+ return addr;
+}
+
--
error compiling committee.c: too many arguments to function
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