[PATCH v3 11/37] whpx: i386: IO port fast path cleanup

[Mohamed Mediouni <mohamed@unpredictable.fr>]

vmport calls synchronise_state within an I/O port read.
Support that properly.

What was there before worked because of a side effect of
whpx_get_reg synchronising context if cpu->vcpu_dirty.

Remove that whpx_get_reg call in whpx_bump_rip too as it's no longer
needed now.

Signed-off-by: Mohamed Mediouni <mohamed@unpredictable.fr>
---
 target/i386/whpx/whpx-all.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/target/i386/whpx/whpx-all.c b/target/i386/whpx/whpx-all.c
index ab8e97787f..75f0f062d4 100644
--- a/target/i386/whpx/whpx-all.c
+++ b/target/i386/whpx/whpx-all.c
@@ -881,7 +881,6 @@ static void handle_io(CPUState *env, uint16_t port, void *buffer,
 static void whpx_bump_rip(CPUState *cpu, WHV_RUN_VP_EXIT_CONTEXT *exit_ctx)
 {
     WHV_REGISTER_VALUE reg;
-    whpx_get_reg(cpu, WHvX64RegisterRip, &reg);
     reg.Reg64 = exit_ctx->VpContext.Rip + exit_ctx->VpContext.InstructionLength;
     whpx_set_reg(cpu, WHvX64RegisterRip, reg);
 }
@@ -909,13 +908,23 @@ static int whpx_handle_portio(CPUState *cpu,
         } else {
             reg.Reg64 = (uint64_t)val;
         }
-        whpx_bump_rip(cpu, exit_ctx);
-        whpx_set_reg(cpu, WHvX64RegisterRax, reg);
+        /* vmport calls cpu_synchronize_state on an I/O port read */
+        if (!cpu->vcpu_dirty) {
+            whpx_bump_rip(cpu, exit_ctx);
+            whpx_set_reg(cpu, WHvX64RegisterRax, reg);
+        } else {
+            env->eip = exit_ctx->VpContext.Rip + exit_ctx->VpContext.InstructionLength;
+            env->regs[R_EAX] = reg.Reg64;
+        }
         return 0;
     } else if (!ctx->AccessInfo.StringOp && ctx->AccessInfo.IsWrite) {
         RAX(env) = ctx->Rax;
         handle_io(cpu, ctx->PortNumber, &RAX(env), 1, ctx->AccessInfo.AccessSize, 1);
-        whpx_bump_rip(cpu, exit_ctx);
+        if (!cpu->vcpu_dirty) {
+            whpx_bump_rip(cpu, exit_ctx);
+        } else {
+            env->eip = exit_ctx->VpContext.Rip + exit_ctx->VpContext.InstructionLength;
+        }
         return 0;
     }
 
-- 
2.50.1 (Apple Git-155)