The original function doesn't distinguish between Valid and Invalid
VMfails. Improved function returns error code depending on the outcome:
VMsucceed: 0
VMfailValid: VM Instruction Error Number
VMfailInvalid: VMX_INSN_FAIL_INVALID (~0)
Existing users of __vmread_safe() are updated and double underscore
prefix is removed from the function's name because such prefixes are
reserved to a compiler.
Signed-off-by: Sergey Dyasli
---
v2 --> v3:
* vmread_safe() now returns "enum vmx_insn_errno" (32-bit value)
xen/arch/x86/hvm/vmx/vmcs.c | 2 +-
xen/arch/x86/hvm/vmx/vvmx.c | 2 +-
xen/include/asm-x86/hvm/vmx/vmx.h | 41 +--
3 files changed, 20 insertions(+), 25 deletions(-)
diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c
index 59ef199..24f7570 100644
--- a/xen/arch/x86/hvm/vmx/vmcs.c
+++ b/xen/arch/x86/hvm/vmx/vmcs.c
@@ -1711,7 +1711,7 @@ static inline unsigned long vmr(unsigned long field)
{
unsigned long val;
-return __vmread_safe(field, &val) ? val : 0;
+return vmread_safe(field, &val) ? 0 : val;
}
#define vmr16(fld) ({ \
diff --git a/xen/arch/x86/hvm/vmx/vvmx.c b/xen/arch/x86/hvm/vmx/vvmx.c
index 105a3c0..31ac360 100644
--- a/xen/arch/x86/hvm/vmx/vvmx.c
+++ b/xen/arch/x86/hvm/vmx/vvmx.c
@@ -932,7 +932,7 @@ static inline void shadow_to_vvmcs(const struct vcpu *v,
unsigned int field)
{
unsigned long value;
-if ( __vmread_safe(field, &value) )
+if ( vmread_safe(field, &value) == 0 )
set_vvmcs(v, field, value);
}
diff --git a/xen/include/asm-x86/hvm/vmx/vmx.h
b/xen/include/asm-x86/hvm/vmx/vmx.h
index 9bfe71a..3e809d4 100644
--- a/xen/include/asm-x86/hvm/vmx/vmx.h
+++ b/xen/include/asm-x86/hvm/vmx/vmx.h
@@ -401,32 +401,27 @@ static always_inline void __vmwrite(unsigned long field,
unsigned long value)
);
}
-static inline bool_t __vmread_safe(unsigned long field, unsigned long *value)
+static inline enum vmx_insn_errno vmread_safe(unsigned long field,
+ unsigned long *value)
{
-bool_t okay;
+unsigned long ret = 0;
+bool fail_invalid, fail_valid;
-asm volatile (
-#ifdef HAVE_GAS_VMX
- "vmread %2, %1\n\t"
-#else
- VMREAD_OPCODE MODRM_EAX_ECX
-#endif
- /* CF==1 or ZF==1 --> rc = 0 */
-#ifdef __GCC_ASM_FLAG_OUTPUTS__
- : "=@ccnbe" (okay),
-#else
- "setnbe %0"
- : "=qm" (okay),
-#endif
-#ifdef HAVE_GAS_VMX
- "=rm" (*value)
- : "r" (field));
-#else
- "=c" (*value)
- : "a" (field));
-#endif
+asm volatile ( GAS_VMX_OP("vmread %[field], %[value]\n\t",
+ VMREAD_OPCODE MODRM_EAX_ECX)
+ ASM_FLAG_OUT(, "setc %[invalid]\n\t")
+ ASM_FLAG_OUT(, "setz %[valid]\n\t")
+ : ASM_FLAG_OUT("=@ccc", [invalid] "=rm") (fail_invalid),
+ ASM_FLAG_OUT("=@ccz", [valid] "=rm") (fail_valid),
+ [value] GAS_VMX_OP("=rm", "=c") (*value)
+ : [field] GAS_VMX_OP("r", "a") (field));
+
+if ( unlikely(fail_invalid) )
+ret = VMX_INSN_FAIL_INVALID;
+else if ( unlikely(fail_valid) )
+__vmread(VM_INSTRUCTION_ERROR, &ret);
-return okay;
+return ret;
}
static inline enum vmx_insn_errno vmwrite_safe(unsigned long field,
--
2.9.3
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