[Xen-devel] [PATCH 3/3] x86/svm: correct EFER.SVME intercept checks

[Brian Woods <brian.woods@xxxxxxx>]

Corrects some EFER.SVME checks in intercepts.  See AMD APM vol2 section
15.4 for more details.  VMMCALL isn't checked due to guests needing it
to boot.

Reported-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Signed-off-by: Brian Woods <brian.woods@xxxxxxx>
---
 xen/arch/x86/hvm/svm/nestedsvm.c | 10 ++++++++--
 xen/arch/x86/hvm/svm/svm.c       |  8 +++++---
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/xen/arch/x86/hvm/svm/nestedsvm.c b/xen/arch/x86/hvm/svm/nestedsvm.c
index 1f7b0d3e88..1f5981fc18 100644
--- a/xen/arch/x86/hvm/svm/nestedsvm.c
+++ b/xen/arch/x86/hvm/svm/nestedsvm.c
@@ -1620,7 +1620,12 @@ void svm_vmexit_do_stgi(struct cpu_user_regs *regs, 
struct vcpu *v)
 {
     unsigned int inst_len;
 
-    if ( !nestedhvm_enabled(v->domain) ) {
+    /*
+     * STGI doesn't require SVME to be set to be used.  See AMD APM vol
+     * 2 section 15.4 for details.
+     */
+    if ( !nestedhvm_enabled(v->domain) )
+    {
         hvm_inject_hw_exception(TRAP_invalid_op, X86_EVENT_NO_EC);
         return;
     }
@@ -1640,7 +1645,8 @@ void svm_vmexit_do_clgi(struct cpu_user_regs *regs, 
struct vcpu *v)
     uint32_t general1_intercepts = vmcb_get_general1_intercepts(vmcb);
     vintr_t intr;
 
-    if ( !nestedhvm_enabled(v->domain) ) {
+    if ( !nsvm_efer_svm_enabled(v) )
+    {
         hvm_inject_hw_exception(TRAP_invalid_op, X86_EVENT_NO_EC);
         return;
     }
diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c
index 7864ee39ae..2599f02ab6 100644
--- a/xen/arch/x86/hvm/svm/svm.c
+++ b/xen/arch/x86/hvm/svm/svm.c
@@ -2255,7 +2255,6 @@ svm_vmexit_do_vmrun(struct cpu_user_regs *regs,
 {
     if ( !nsvm_efer_svm_enabled(v) )
     {
-        gdprintk(XENLOG_ERR, "VMRUN: nestedhvm disabled, injecting #UD\n");
         hvm_inject_hw_exception(TRAP_invalid_op, X86_EVENT_NO_EC);
         return;
     }
@@ -2310,7 +2309,6 @@ svm_vmexit_do_vmload(struct vmcb_struct *vmcb,
 
     if ( !nsvm_efer_svm_enabled(v) ) 
     {
-        gdprintk(XENLOG_ERR, "VMLOAD: nestedhvm disabled, injecting #UD\n");
         hvm_inject_hw_exception(TRAP_invalid_op, X86_EVENT_NO_EC);
         return;
     }
@@ -2346,7 +2344,6 @@ svm_vmexit_do_vmsave(struct vmcb_struct *vmcb,
 
     if ( !nsvm_efer_svm_enabled(v) ) 
     {
-        gdprintk(XENLOG_ERR, "VMSAVE: nestedhvm disabled, injecting #UD\n");
         hvm_inject_hw_exception(TRAP_invalid_op, X86_EVENT_NO_EC);
         return;
     }
@@ -2820,6 +2817,11 @@ void svm_vmexit_handler(struct cpu_user_regs *regs)
         break;
 
     case VMEXIT_INVLPGA:
+        if ( !nsvm_efer_svm_enabled(v) )
+        {
+            hvm_inject_hw_exception(TRAP_invalid_op, X86_EVENT_NO_EC);
+            break;
+        }
         if ( (inst_len = __get_instruction_length(v, INSTR_INVLPGA)) == 0 )
             break;
         svm_invlpga_intercept(v, regs->rax, regs->ecx);
-- 
2.11.0


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