KVM: x86: accessors for guest registers

As suggested by Avi, introduce accessors to read/write guest registers.
This simplifies the ->cache_regs/->decache_regs interface, and improves
register caching which is important for VMX, where the cost of
vmcs_read/vmcs_write is significant.

[avi: fix warnings]

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 10 insertions, 5 deletions

diff --git a/include/asm-x86/kvm_host.h b/include/asm-x86/kvm_host.h
index 69794547f514..8c886be0103f 100644
--- a/include/asm-x86/kvm_host.h
+++ b/include/asm-x86/kvm_host.h
@@ -89,7 +89,7 @@ extern struct list_head vm_list;
 struct kvm_vcpu;
 struct kvm;
 
-enum {
+enum kvm_reg {
         VCPU_REGS_RAX = 0,
         VCPU_REGS_RCX = 1,
         VCPU_REGS_RDX = 2,
@@ -108,6 +108,7 @@ enum {
         VCPU_REGS_R14 = 14,
         VCPU_REGS_R15 = 15,
 #endif
+        VCPU_REGS_RIP,
         NR_VCPU_REGS
 };
 
@@ -219,8 +220,13 @@ struct kvm_vcpu_arch {
         int interrupt_window_open;
         unsigned long irq_summary; /* bit vector: 1 per word in irq_pending */
         DECLARE_BITMAP(irq_pending, KVM_NR_INTERRUPTS);
-        unsigned long regs[NR_VCPU_REGS]; /* for rsp: vcpu_load_rsp_rip() */
-        unsigned long rip;      /* needs vcpu_load_rsp_rip() */
+        /*
+         * rip and regs accesses must go through
+         * kvm_{register,rip}_{read,write} functions.
+         */
+        unsigned long regs[NR_VCPU_REGS];
+        u32 regs_avail;
+        u32 regs_dirty;
 
         unsigned long cr0;
         unsigned long cr2;
@@ -414,8 +420,7 @@ struct kvm_x86_ops {
         unsigned long (*get_dr)(struct kvm_vcpu *vcpu, int dr);
         void (*set_dr)(struct kvm_vcpu *vcpu, int dr, unsigned long value,
                        int *exception);
-        void (*cache_regs)(struct kvm_vcpu *vcpu);
-        void (*decache_regs)(struct kvm_vcpu *vcpu);
+        void (*cache_reg)(struct kvm_vcpu *vcpu, enum kvm_reg reg);
         unsigned long (*get_rflags)(struct kvm_vcpu *vcpu);
         void (*set_rflags)(struct kvm_vcpu *vcpu, unsigned long rflags);