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Diffstat (limited to 'arch/x86/kvm/vmx/vmx_ops.h')
-rw-r--r--arch/x86/kvm/vmx/vmx_ops.h20
1 files changed, 17 insertions, 3 deletions
diff --git a/arch/x86/kvm/vmx/vmx_ops.h b/arch/x86/kvm/vmx/vmx_ops.h
index ec268df83ed6..842dc898c972 100644
--- a/arch/x86/kvm/vmx/vmx_ops.h
+++ b/arch/x86/kvm/vmx/vmx_ops.h
@@ -6,19 +6,33 @@
#include <asm/vmx.h>
-#include "evmcs.h"
+#include "hyperv.h"
#include "vmcs.h"
#include "../x86.h"
void vmread_error(unsigned long field, bool fault);
-__attribute__((regparm(0))) void vmread_error_trampoline(unsigned long field,
- bool fault);
void vmwrite_error(unsigned long field, unsigned long value);
void vmclear_error(struct vmcs *vmcs, u64 phys_addr);
void vmptrld_error(struct vmcs *vmcs, u64 phys_addr);
void invvpid_error(unsigned long ext, u16 vpid, gva_t gva);
void invept_error(unsigned long ext, u64 eptp, gpa_t gpa);
+#ifndef CONFIG_CC_HAS_ASM_GOTO_OUTPUT
+/*
+ * The VMREAD error trampoline _always_ uses the stack to pass parameters, even
+ * for 64-bit targets. Preserving all registers allows the VMREAD inline asm
+ * blob to avoid clobbering GPRs, which in turn allows the compiler to better
+ * optimize sequences of VMREADs.
+ *
+ * Declare the trampoline as an opaque label as it's not safe to call from C
+ * code; there is no way to tell the compiler to pass params on the stack for
+ * 64-bit targets.
+ *
+ * void vmread_error_trampoline(unsigned long field, bool fault);
+ */
+extern unsigned long vmread_error_trampoline;
+#endif
+
static __always_inline void vmcs_check16(unsigned long field)
{
BUILD_BUG_ON_MSG(__builtin_constant_p(field) && ((field) & 0x6001) == 0x2000,