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, 9 deletions

diff --git a/arch/x86/kvm/x86_emulate.c b/arch/x86/kvm/x86_emulate.c
index f2f90468f8b1..d5da7f14d536 100644
--- a/arch/x86/kvm/x86_emulate.c
+++ b/arch/x86/kvm/x86_emulate.c
@@ -26,6 +26,7 @@
 #define DPRINTF(_f, _a ...) printf(_f , ## _a)
 #else
 #include <linux/kvm_host.h>
+#include "kvm_cache_regs.h"
 #define DPRINTF(x...) do {} while (0)
 #endif
 #include <linux/module.h>
@@ -839,7 +840,7 @@ x86_decode_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
         /* Shadow copy of register state. Committed on successful emulation. */
 
         memset(c, 0, sizeof(struct decode_cache));
-        c->eip = ctxt->vcpu->arch.rip;
+        c->eip = kvm_rip_read(ctxt->vcpu);
         ctxt->cs_base = seg_base(ctxt, VCPU_SREG_CS);
         memcpy(c->regs, ctxt->vcpu->arch.regs, sizeof c->regs);
 
@@ -1267,7 +1268,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
         if (c->rep_prefix && (c->d & String)) {
                 /* All REP prefixes have the same first termination condition */
                 if (c->regs[VCPU_REGS_RCX] == 0) {
-                        ctxt->vcpu->arch.rip = c->eip;
+                        kvm_rip_write(ctxt->vcpu, c->eip);
                         goto done;
                 }
                 /* The second termination condition only applies for REPE
@@ -1281,17 +1282,17 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
                                 (c->b == 0xae) || (c->b == 0xaf)) {
                         if ((c->rep_prefix == REPE_PREFIX) &&
                                 ((ctxt->eflags & EFLG_ZF) == 0)) {
-                                        ctxt->vcpu->arch.rip = c->eip;
+                                        kvm_rip_write(ctxt->vcpu, c->eip);
                                         goto done;
                         }
                         if ((c->rep_prefix == REPNE_PREFIX) &&
                                 ((ctxt->eflags & EFLG_ZF) == EFLG_ZF)) {
-                                ctxt->vcpu->arch.rip = c->eip;
+                                kvm_rip_write(ctxt->vcpu, c->eip);
                                 goto done;
                         }
                 }
                 c->regs[VCPU_REGS_RCX]--;
-                c->eip = ctxt->vcpu->arch.rip;
+                c->eip = kvm_rip_read(ctxt->vcpu);
         }
 
         if (c->src.type == OP_MEM) {
@@ -1768,7 +1769,7 @@ writeback:
 
         /* Commit shadow register state. */
         memcpy(ctxt->vcpu->arch.regs, c->regs, sizeof c->regs);
-        ctxt->vcpu->arch.rip = c->eip;
+        kvm_rip_write(ctxt->vcpu, c->eip);
 
 done:
         if (rc == X86EMUL_UNHANDLEABLE) {
@@ -1793,7 +1794,7 @@ twobyte_insn:
                                 goto done;
 
                         /* Let the processor re-execute the fixed hypercall */
-                        c->eip = ctxt->vcpu->arch.rip;
+                        c->eip = kvm_rip_read(ctxt->vcpu);
                         /* Disable writeback. */
                         c->dst.type = OP_NONE;
                         break;
@@ -1889,7 +1890,7 @@ twobyte_insn:
                 rc = kvm_set_msr(ctxt->vcpu, c->regs[VCPU_REGS_RCX], msr_data);
                 if (rc) {
                         kvm_inject_gp(ctxt->vcpu, 0);
-                        c->eip = ctxt->vcpu->arch.rip;
+                        c->eip = kvm_rip_read(ctxt->vcpu);
                 }
                 rc = X86EMUL_CONTINUE;
                 c->dst.type = OP_NONE;
@@ -1899,7 +1900,7 @@ twobyte_insn:
                 rc = kvm_get_msr(ctxt->vcpu, c->regs[VCPU_REGS_RCX], &msr_data);
                 if (rc) {
                         kvm_inject_gp(ctxt->vcpu, 0);
-                        c->eip = ctxt->vcpu->arch.rip;
+                        c->eip = kvm_rip_read(ctxt->vcpu);
                 } else {
                         c->regs[VCPU_REGS_RAX] = (u32)msr_data;
                         c->regs[VCPU_REGS_RDX] = msr_data >> 32;