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-rw-r--r--Documentation/virtual/kvm/api.txt23
-rw-r--r--arch/ia64/include/asm/kvm.h4
-rw-r--r--arch/powerpc/include/asm/kvm.h4
-rw-r--r--arch/s390/include/asm/kvm.h3
-rw-r--r--arch/x86/include/asm/kvm.h4
-rw-r--r--include/linux/kvm.h15
6 files changed, 53 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index a67fb35993fa..7ca696227d3a 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -1771,6 +1771,29 @@ developer registration required to access it).
/* Fix the size of the union. */
char padding[256];
};
+
+ /*
+ * shared registers between kvm and userspace.
+ * kvm_valid_regs specifies the register classes set by the host
+ * kvm_dirty_regs specified the register classes dirtied by userspace
+ * struct kvm_sync_regs is architecture specific, as well as the
+ * bits for kvm_valid_regs and kvm_dirty_regs
+ */
+ __u64 kvm_valid_regs;
+ __u64 kvm_dirty_regs;
+ union {
+ struct kvm_sync_regs regs;
+ char padding[1024];
+ } s;
+
+If KVM_CAP_SYNC_REGS is defined, these fields allow userspace to access
+certain guest registers without having to call SET/GET_*REGS. Thus we can
+avoid some system call overhead if userspace has to handle the exit.
+Userspace can query the validity of the structure by checking
+kvm_valid_regs for specific bits. These bits are architecture specific
+and usually define the validity of a groups of registers. (e.g. one bit
+ for general purpose registers)
+
};
6. Capabilities that can be enabled
diff --git a/arch/ia64/include/asm/kvm.h b/arch/ia64/include/asm/kvm.h
index bc90c75adf67..b9f82c84f093 100644
--- a/arch/ia64/include/asm/kvm.h
+++ b/arch/ia64/include/asm/kvm.h
@@ -261,4 +261,8 @@ struct kvm_debug_exit_arch {
struct kvm_guest_debug_arch {
};
+/* definition of registers in kvm_run */
+struct kvm_sync_regs {
+};
+
#endif
diff --git a/arch/powerpc/include/asm/kvm.h b/arch/powerpc/include/asm/kvm.h
index f7727d91ac6b..7d9d4de057ef 100644
--- a/arch/powerpc/include/asm/kvm.h
+++ b/arch/powerpc/include/asm/kvm.h
@@ -265,6 +265,10 @@ struct kvm_debug_exit_arch {
struct kvm_guest_debug_arch {
};
+/* definition of registers in kvm_run */
+struct kvm_sync_regs {
+};
+
#define KVM_REG_MASK 0x001f
#define KVM_REG_EXT_MASK 0xffe0
#define KVM_REG_GPR 0x0000
diff --git a/arch/s390/include/asm/kvm.h b/arch/s390/include/asm/kvm.h
index 82b32a100c7d..325560afb77e 100644
--- a/arch/s390/include/asm/kvm.h
+++ b/arch/s390/include/asm/kvm.h
@@ -41,4 +41,7 @@ struct kvm_debug_exit_arch {
struct kvm_guest_debug_arch {
};
+/* definition of registers in kvm_run */
+struct kvm_sync_regs {
+};
#endif
diff --git a/arch/x86/include/asm/kvm.h b/arch/x86/include/asm/kvm.h
index 4d8dcbdfc120..e7d1c194d272 100644
--- a/arch/x86/include/asm/kvm.h
+++ b/arch/x86/include/asm/kvm.h
@@ -321,4 +321,8 @@ struct kvm_xcrs {
__u64 padding[16];
};
+/* definition of registers in kvm_run */
+struct kvm_sync_regs {
+};
+
#endif /* _ASM_X86_KVM_H */
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 6cf048d9604b..245bcb3a0fcd 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -279,6 +279,20 @@ struct kvm_run {
/* Fix the size of the union. */
char padding[256];
};
+
+ /*
+ * shared registers between kvm and userspace.
+ * kvm_valid_regs specifies the register classes set by the host
+ * kvm_dirty_regs specified the register classes dirtied by userspace
+ * struct kvm_sync_regs is architecture specific, as well as the
+ * bits for kvm_valid_regs and kvm_dirty_regs
+ */
+ __u64 kvm_valid_regs;
+ __u64 kvm_dirty_regs;
+ union {
+ struct kvm_sync_regs regs;
+ char padding[1024];
+ } s;
};
/* for KVM_REGISTER_COALESCED_MMIO / KVM_UNREGISTER_COALESCED_MMIO */
@@ -570,6 +584,7 @@ struct kvm_ppc_pvinfo {
#define KVM_CAP_S390_GMAP 71
#define KVM_CAP_TSC_DEADLINE_TIMER 72
#define KVM_CAP_S390_UCONTROL 73
+#define KVM_CAP_SYNC_REGS 74
#ifdef KVM_CAP_IRQ_ROUTING