[RFC v1 6/7] x86/svm: Use the emulator path for VMEXIT_HLT

[Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>]

Signed-off-by: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>
---
 xen/arch/x86/hvm/emulate.c     |  5 +++++
 xen/arch/x86/hvm/svm/emulate.c |  2 +-
 xen/arch/x86/hvm/svm/svm.c     | 24 +++++++++++-------------
 xen/arch/x86/hvm/svm/svm.h     |  1 +
 4 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/xen/arch/x86/hvm/emulate.c b/xen/arch/x86/hvm/emulate.c
index c9553cd28238..471c032c1e9c 100644
--- a/xen/arch/x86/hvm/emulate.c
+++ b/xen/arch/x86/hvm/emulate.c
@@ -2800,6 +2800,11 @@ static int _hvm_emulate_one(struct hvm_emulate_ctxt 
*hvmemul_ctxt,
 
         switch ( hvmemul_ctxt->insn )
         {
+        case INSTR_HLT:
+            hvmemul_ctxt->ctxt.retire.hlt = true;
+            rc = X86EMUL_OKAY;
+            break;
+
         default:
             ASSERT_UNREACHABLE();
             rc = X86EMUL_UNHANDLEABLE;
diff --git a/xen/arch/x86/hvm/svm/emulate.c b/xen/arch/x86/hvm/svm/emulate.c
index 1dd830a31bd7..31f3cd88a858 100644
--- a/xen/arch/x86/hvm/svm/emulate.c
+++ b/xen/arch/x86/hvm/svm/emulate.c
@@ -16,7 +16,7 @@
 #include "svm.h"
 #include "vmcb.h"
 
-static unsigned long svm_nextrip_insn_length(struct vcpu *v)
+unsigned long svm_nextrip_insn_length(struct vcpu *v)
 {
     struct vmcb_struct *vmcb = v->arch.hvm.svm.vmcb;
 
diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c
index f49d2ebbfdd5..2d6022d6238c 100644
--- a/xen/arch/x86/hvm/svm/svm.c
+++ b/xen/arch/x86/hvm/svm/svm.c
@@ -2051,18 +2051,6 @@ static void svm_do_msr_access(struct cpu_user_regs *regs)
         hvm_inject_hw_exception(X86_EXC_GP, 0);
 }
 
-static void svm_vmexit_do_hlt(struct vmcb_struct *vmcb,
-                              struct cpu_user_regs *regs)
-{
-    unsigned int inst_len;
-
-    if ( (inst_len = svm_get_insn_len(current, INSTR_HLT)) == 0 )
-        return;
-    __update_guest_eip(regs, inst_len);
-
-    hvm_hlt(regs->eflags);
-}
-
 static void svm_vmexit_do_rdtsc(struct cpu_user_regs *regs, bool rdtscp)
 {
     struct vcpu *curr = current;
@@ -2363,6 +2351,13 @@ static void cf_check svm_set_reg(struct vcpu *v, 
unsigned int reg, uint64_t val)
     }
 }
 
+static void svm_emulate_one(struct hvm_emulate_ctxt *ctxt)
+{
+    ctxt->insn_len = svm_nextrip_insn_length(current);
+    if ( !hvm_emulate_one_ctxt(ctxt) )
+        hvm_inject_hw_exception(X86_EXC_GP, 0);
+}
+
 static struct hvm_function_table __initdata_cf_clobber svm_function_table = {
     .name                 = "SVM",
     .cpu_up_prepare       = svm_cpu_up_prepare,
@@ -2496,6 +2491,7 @@ void asmlinkage svm_vmexit_handler(void)
     vintr_t intr;
     bool vcpu_guestmode = false;
     struct vlapic *vlapic = vcpu_vlapic(v);
+    struct hvm_emulate_ctxt ctxt;
 
     regs->rax = vmcb->rax;
     regs->rip = vmcb->rip;
@@ -2840,7 +2836,9 @@ void asmlinkage svm_vmexit_handler(void)
     }
 
     case VMEXIT_HLT:
-        svm_vmexit_do_hlt(vmcb, regs);
+        hvm_emulate_init_once(&ctxt, NULL, NULL, regs);
+        ctxt.insn = INSTR_HLT;
+        svm_emulate_one(&ctxt);
         break;
 
     case VMEXIT_IOIO:
diff --git a/xen/arch/x86/hvm/svm/svm.h b/xen/arch/x86/hvm/svm/svm.h
index f75bca7c5f66..9422dbd38a78 100644
--- a/xen/arch/x86/hvm/svm/svm.h
+++ b/xen/arch/x86/hvm/svm/svm.h
@@ -36,6 +36,7 @@ static inline void svm_invlpga(unsigned long linear, uint32_t 
asid)
     asm volatile ( "invlpga" :: "a" (linear), "c" (asid) );
 }
 
+unsigned long svm_nextrip_insn_length(struct vcpu *v);
 unsigned int svm_get_insn_len(struct vcpu *v, unsigned int instr_enc);
 unsigned int svm_get_task_switch_insn_len(void);
 
-- 
2.53.0