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authorChristian Borntraeger <borntraeger@de.ibm.com>2007-10-11 15:34:17 +0200
committerAvi Kivity <avi@qumranet.com>2008-01-30 17:52:55 +0200
commit5f43238d036fb30e73563e81e42d9c6f1de5551a (patch)
tree5188b44c4c34b75ae61eca7465df23aa448546a2 /include/asm-x86/kvm_para.h
parent8c392696e749171531d155ea5cefdfc1c970fd18 (diff)
KVM: Per-architecture hypercall definitions
Currently kvm provides hypercalls only for x86* architectures. To provide hypercall infrastructure for other kvm architectures I split kvm_para.h into a generic header file and architecture specific definitions. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'include/asm-x86/kvm_para.h')
-rw-r--r--include/asm-x86/kvm_para.h105
1 files changed, 105 insertions, 0 deletions
diff --git a/include/asm-x86/kvm_para.h b/include/asm-x86/kvm_para.h
new file mode 100644
index 000000000000..c6f3fd8d8c53
--- /dev/null
+++ b/include/asm-x86/kvm_para.h
@@ -0,0 +1,105 @@
+#ifndef __X86_KVM_PARA_H
+#define __X86_KVM_PARA_H
+
+/* This CPUID returns the signature 'KVMKVMKVM' in ebx, ecx, and edx. It
+ * should be used to determine that a VM is running under KVM.
+ */
+#define KVM_CPUID_SIGNATURE 0x40000000
+
+/* This CPUID returns a feature bitmap in eax. Before enabling a particular
+ * paravirtualization, the appropriate feature bit should be checked.
+ */
+#define KVM_CPUID_FEATURES 0x40000001
+
+#ifdef __KERNEL__
+#include <asm/processor.h>
+
+/* This instruction is vmcall. On non-VT architectures, it will generate a
+ * trap that we will then rewrite to the appropriate instruction.
+ */
+#define KVM_HYPERCALL ".byte 0x0f,0x01,0xc1"
+
+/* For KVM hypercalls, a three-byte sequence of either the vmrun or the vmmrun
+ * instruction. The hypervisor may replace it with something else but only the
+ * instructions are guaranteed to be supported.
+ *
+ * Up to four arguments may be passed in rbx, rcx, rdx, and rsi respectively.
+ * The hypercall number should be placed in rax and the return value will be
+ * placed in rax. No other registers will be clobbered unless explicited
+ * noted by the particular hypercall.
+ */
+
+static inline long kvm_hypercall0(unsigned int nr)
+{
+ long ret;
+ asm volatile(KVM_HYPERCALL
+ : "=a"(ret)
+ : "a"(nr));
+ return ret;
+}
+
+static inline long kvm_hypercall1(unsigned int nr, unsigned long p1)
+{
+ long ret;
+ asm volatile(KVM_HYPERCALL
+ : "=a"(ret)
+ : "a"(nr), "b"(p1));
+ return ret;
+}
+
+static inline long kvm_hypercall2(unsigned int nr, unsigned long p1,
+ unsigned long p2)
+{
+ long ret;
+ asm volatile(KVM_HYPERCALL
+ : "=a"(ret)
+ : "a"(nr), "b"(p1), "c"(p2));
+ return ret;
+}
+
+static inline long kvm_hypercall3(unsigned int nr, unsigned long p1,
+ unsigned long p2, unsigned long p3)
+{
+ long ret;
+ asm volatile(KVM_HYPERCALL
+ : "=a"(ret)
+ : "a"(nr), "b"(p1), "c"(p2), "d"(p3));
+ return ret;
+}
+
+static inline long kvm_hypercall4(unsigned int nr, unsigned long p1,
+ unsigned long p2, unsigned long p3,
+ unsigned long p4)
+{
+ long ret;
+ asm volatile(KVM_HYPERCALL
+ : "=a"(ret)
+ : "a"(nr), "b"(p1), "c"(p2), "d"(p3), "S"(p4));
+ return ret;
+}
+
+static inline int kvm_para_available(void)
+{
+ unsigned int eax, ebx, ecx, edx;
+ char signature[13];
+
+ cpuid(KVM_CPUID_SIGNATURE, &eax, &ebx, &ecx, &edx);
+ memcpy(signature + 0, &ebx, 4);
+ memcpy(signature + 4, &ecx, 4);
+ memcpy(signature + 8, &edx, 4);
+ signature[12] = 0;
+
+ if (strcmp(signature, "KVMKVMKVM") == 0)
+ return 1;
+
+ return 0;
+}
+
+static inline unsigned int kvm_arch_para_features(void)
+{
+ return cpuid_eax(KVM_CPUID_FEATURES);
+}
+
+#endif
+
+#endif