From: Keir Fraser <keir@xensource.com>
Date: Fri, 28 Sep 2007 14:03:50 +0000 (+0100)
Subject: hvm: Enable HAP by default (NPT on AMD SVM systems).
X-Git-Tag: 3.2.0-rc1~305^2~6
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=65c67b479214731a9064474fd14133f3043bf84d;p=xen.git

hvm: Enable HAP by default (NPT on AMD SVM systems).
Signed-off-by: Keir Fraser <keir@xensource.com>
---

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index d77262eb39..447b158a27 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -49,6 +49,10 @@
 #include <public/version.h>
 #include <public/memory.h>
 
+/* Xen command-line option to disable hardware-assisted paging */
+static int opt_hap_disabled;
+invbool_param("hap", opt_hap_disabled);
+
 int hvm_enabled __read_mostly;
 
 unsigned int opt_hvm_debug_level __read_mostly;
@@ -74,6 +78,14 @@ void hvm_enable(struct hvm_function_table *fns)
 
     hvm_funcs   = *fns;
     hvm_enabled = 1;
+
+    if ( hvm_funcs.hap_supported )
+    {
+        if ( opt_hap_disabled )
+            hvm_funcs.hap_supported = 0;
+        printk("HVM: Hardware Assisted Paging %sabled\n",
+               hvm_funcs.hap_supported ? "en" : "dis");
+    }
 }
 
 void hvm_set_guest_time(struct vcpu *v, u64 gtime)
diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c
index d0cc5f21cd..d6db5bf028 100644
--- a/xen/arch/x86/hvm/svm/svm.c
+++ b/xen/arch/x86/hvm/svm/svm.c
@@ -69,9 +69,6 @@ static void *hsa[NR_CPUS] __read_mostly;
 /* vmcb used for extended host state */
 static void *root_vmcb[NR_CPUS] __read_mostly;
 
-/* hardware assisted paging bits */
-extern int opt_hap_enabled;
-
 static void inline __update_guest_eip(
     struct cpu_user_regs *regs, int inst_len) 
 {
@@ -936,18 +933,14 @@ static struct hvm_function_table svm_function_table = {
     .event_pending        = svm_event_pending
 };
 
-static void svm_npt_detect(void)
+static int svm_npt_detect(void)
 {
     u32 eax, ebx, ecx, edx;
 
     /* Check CPUID for nested paging support. */
     cpuid(0x8000000A, &eax, &ebx, &ecx, &edx);
 
-    if ( !(edx & 1) && opt_hap_enabled )
-    {
-        printk("SVM: Nested paging is not supported by this CPU.\n");
-        opt_hap_enabled = 0;
-    }
+    return (edx & 1);
 }
 
 int start_svm(struct cpuinfo_x86 *c)
@@ -978,8 +971,6 @@ int start_svm(struct cpuinfo_x86 *c)
 
     write_efer(read_efer() | EFER_SVME);
 
-    svm_npt_detect();
-
     /* Initialize the HSA for this core. */
     phys_hsa = (u64) virt_to_maddr(hsa[cpu]);
     phys_hsa_lo = (u32) phys_hsa;
@@ -994,11 +985,10 @@ int start_svm(struct cpuinfo_x86 *c)
 
     setup_vmcb_dump();
 
+    svm_function_table.hap_supported = svm_npt_detect();
+
     hvm_enable(&svm_function_table);
 
-    if ( opt_hap_enabled )
-        printk("SVM: Nested paging enabled.\n");
-        
     return 1;
 }
 
diff --git a/xen/arch/x86/mm/paging.c b/xen/arch/x86/mm/paging.c
index 25f323151d..a8c56b175d 100644
--- a/xen/arch/x86/mm/paging.c
+++ b/xen/arch/x86/mm/paging.c
@@ -28,9 +28,7 @@
 #include <asm/guest_access.h>
 #include <xsm/xsm.h>
 
-/* Xen command-line option to enable hardware-assisted paging */
-int opt_hap_enabled;
-boolean_param("hap", opt_hap_enabled);
+#define hap_enabled(d) (hvm_funcs.hap_supported && is_hvm_domain(d))
 
 /* Printouts */
 #define PAGING_PRINTK(_f, _a...)                                     \
@@ -363,14 +361,14 @@ void paging_domain_init(struct domain *d)
     shadow_domain_init(d);
 
     /* ... but we will use hardware assistance if it's available. */
-    if ( opt_hap_enabled && is_hvm_domain(d) )
+    if ( hap_enabled(d) )
         hap_domain_init(d);
 }
 
 /* vcpu paging struct initialization goes here */
 void paging_vcpu_init(struct vcpu *v)
 {
-    if ( opt_hap_enabled && is_hvm_vcpu(v) )
+    if ( hap_enabled(v->domain) )
         hap_vcpu_init(v);
     else
         shadow_vcpu_init(v);
@@ -434,7 +432,7 @@ int paging_domctl(struct domain *d, xen_domctl_shadow_op_t *sc,
     }
 
     /* Here, dispatch domctl to the appropriate paging code */
-    if ( opt_hap_enabled && is_hvm_domain(d) )
+    if ( hap_enabled(d) )
         return hap_domctl(d, sc, u_domctl);
     else
         return shadow_domctl(d, sc, u_domctl);
@@ -443,7 +441,7 @@ int paging_domctl(struct domain *d, xen_domctl_shadow_op_t *sc,
 /* Call when destroying a domain */
 void paging_teardown(struct domain *d)
 {
-    if ( opt_hap_enabled && is_hvm_domain(d) )
+    if ( hap_enabled(d) )
         hap_teardown(d);
     else
         shadow_teardown(d);
@@ -455,7 +453,7 @@ void paging_teardown(struct domain *d)
 /* Call once all of the references to the domain have gone away */
 void paging_final_teardown(struct domain *d)
 {
-    if ( opt_hap_enabled && is_hvm_domain(d) )
+    if ( hap_enabled(d) )
         hap_final_teardown(d);
     else
         shadow_final_teardown(d);
@@ -465,7 +463,7 @@ void paging_final_teardown(struct domain *d)
  * creation. */
 int paging_enable(struct domain *d, u32 mode)
 {
-    if ( opt_hap_enabled && is_hvm_domain(d) )
+    if ( hap_enabled(d) )
         return hap_enable(d, mode | PG_HAP_enable);
     else
         return shadow_enable(d, mode | PG_SH_enable);
diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h
index f2cc1f99a7..e1af3c20be 100644
--- a/xen/include/asm-x86/hvm/hvm.h
+++ b/xen/include/asm-x86/hvm/hvm.h
@@ -72,6 +72,9 @@ enum hvm_intack {
 struct hvm_function_table {
     char *name;
 
+    /* Support Hardware-Assisted Paging? */
+    int hap_supported;
+
     /*
      * Initialise/destroy HVM domain/vcpu resources
      */