[PATCH v3 1/4] x86/pvh: Set 32b PVH guest mode in XEN_DOMCTL_set_address_size

[Boris Ostrovsky <boris.ostrovsky@oracle.com>]

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
Changes in v3:
* Updated switch_native() not to call release_compat_l4() on PVH guests
* hvm_set_mode() handles both 8 and 4 modes and returns
  -EOPNOTSUPP otherwise. Similar chages to vmx_set_mode()


 xen/arch/x86/domain.c         | 27 ++++++++++++++++-----------
 xen/arch/x86/hvm/hvm.c        | 24 +++++++++++++++++++++++-
 xen/arch/x86/hvm/vmx/vmcs.c   |  2 +-
 xen/arch/x86/hvm/vmx/vmx.c    | 19 +++++++++++++++++++
 xen/include/asm-x86/hvm/hvm.h |  2 ++
 5 files changed, 61 insertions(+), 13 deletions(-)

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 956ac70..9c29ef2 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -366,7 +366,11 @@ int switch_native(struct domain *d)
     for_each_vcpu( d, v )
     {
         free_compat_arg_xlat(v);
-        release_compat_l4(v);
+
+        if ( !is_pvh_domain(d) )
+            release_compat_l4(v);
+        else
+            hvm_set_mode(v, 8);
     }
 
     return 0;
@@ -377,25 +381,26 @@ int switch_compat(struct domain *d)
     struct vcpu *v;
     int rc;
 
-    if ( is_pvh_domain(d) )
-    {
-        printk(XENLOG_G_INFO
-               "Xen currently does not support 32bit PVH guests\n");
-        return -EINVAL;
-    }
-
     if ( !may_switch_mode(d) )
         return -EACCES;
     if ( is_pv_32bit_domain(d) )
         return 0;
 
-    d->arch.is_32bit_pv = d->arch.has_32bit_shinfo = 1;
+    d->arch.has_32bit_shinfo = 1;
+    if ( is_pv_domain(d) )
+        d->arch.is_32bit_pv = 1;
 
     for_each_vcpu( d, v )
     {
         rc = setup_compat_arg_xlat(v);
         if ( !rc )
-            rc = setup_compat_l4(v);
+        {
+            if ( !is_pvh_domain(d) )
+                rc = setup_compat_l4(v);
+            else
+                rc = hvm_set_mode(v, 4);
+        }
+
         if ( rc )
             goto undo_and_fail;
     }
@@ -410,7 +415,7 @@ int switch_compat(struct domain *d)
     {
         free_compat_arg_xlat(v);
 
-        if ( !pagetable_is_null(v->arch.guest_table) )
+        if ( !is_pvh_domain(d) && !pagetable_is_null(v->arch.guest_table) )
             release_compat_l4(v);
     }
 
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index ebcf7a9..6f247a0 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -2373,7 +2373,6 @@ int hvm_vcpu_initialise(struct vcpu *v)
 
     if ( is_pvh_domain(d) )
     {
-        v->arch.hvm_vcpu.hcall_64bit = 1;    /* PVH 32bitfixme. */
         /* This is for hvm_long_mode_enabled(v). */
         v->arch.hvm_vcpu.guest_efer = EFER_LMA | EFER_LME;
         return 0;
@@ -6463,6 +6462,29 @@ void hvm_toggle_singlestep(struct vcpu *v)
     v->arch.hvm_vcpu.single_step = !v->arch.hvm_vcpu.single_step;
 }
 
+int hvm_set_mode(struct vcpu *v, int mode)
+{
+
+    switch ( mode )
+    {
+    case 4:
+        v->arch.hvm_vcpu.guest_efer &= ~(EFER_LMA | EFER_LME);
+        break;
+    case 8:
+        v->arch.hvm_vcpu.guest_efer |= (EFER_LMA | EFER_LME);
+        break;
+    default:
+        return -EOPNOTSUPP;
+    }
+
+    hvm_update_guest_efer(v);
+
+    if ( hvm_funcs.set_mode )
+        return hvm_funcs.set_mode(v, mode);
+
+    return 0;
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c
index 4c5ceb5..55ab7ad 100644
--- a/xen/arch/x86/hvm/vmx/vmcs.c
+++ b/xen/arch/x86/hvm/vmx/vmcs.c
@@ -1125,7 +1125,7 @@ static int construct_vmcs(struct vcpu *v)
     __vmwrite(GUEST_FS_AR_BYTES, 0xc093);
     __vmwrite(GUEST_GS_AR_BYTES, 0xc093);
     if ( is_pvh_domain(d) )
-        /* CS.L == 1, exec, read/write, accessed. PVH 32bitfixme. */
+        /* CS.L == 1, exec, read/write, accessed. */
         __vmwrite(GUEST_CS_AR_BYTES, 0xa09b);
     else
         __vmwrite(GUEST_CS_AR_BYTES, 0xc09b); /* exec/read, accessed */
diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index bc3212f..888dea2 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -1770,6 +1770,24 @@ static bool_t vmx_is_singlestep_supported(void)
     return cpu_has_monitor_trap_flag;
 }
 
+static int vmx_set_mode(struct vcpu *v, int mode)
+{
+    unsigned long attr;
+
+    if ( !is_pvh_vcpu(v) )
+        return 0;
+
+    ASSERT((mode == 4) || (mode == 8));
+
+    attr = (mode == 4) ? 0xc09b : 0xa09b;
+
+    vmx_vmcs_enter(v);
+    __vmwrite(GUEST_CS_AR_BYTES, attr);
+    vmx_vmcs_exit(v);
+
+    return 0;
+}
+
 static struct hvm_function_table __initdata vmx_function_table = {
     .name                 = "VMX",
     .cpu_up_prepare       = vmx_cpu_up_prepare,
@@ -1828,6 +1846,7 @@ static struct hvm_function_table __initdata vmx_function_table = {
     .hypervisor_cpuid_leaf = vmx_hypervisor_cpuid_leaf,
     .enable_msr_exit_interception = vmx_enable_msr_exit_interception,
     .is_singlestep_supported = vmx_is_singlestep_supported,
+    .set_mode = vmx_set_mode,
 };
 
 const struct hvm_function_table * __init start_vmx(void)
diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h
index 35f1300..c35dd19 100644
--- a/xen/include/asm-x86/hvm/hvm.h
+++ b/xen/include/asm-x86/hvm/hvm.h
@@ -203,6 +203,7 @@ struct hvm_function_table {
 
     void (*enable_msr_exit_interception)(struct domain *d);
     bool_t (*is_singlestep_supported)(void);
+    int (*set_mode)(struct vcpu *v, int mode);
 };
 
 extern struct hvm_function_table hvm_funcs;
@@ -237,6 +238,7 @@ void hvm_set_guest_tsc_fixed(struct vcpu *v, u64 guest_tsc, u64 at_tsc);
 u64 hvm_get_guest_tsc_fixed(struct vcpu *v, u64 at_tsc);
 #define hvm_get_guest_tsc(v) hvm_get_guest_tsc_fixed(v, 0)
 
+int hvm_set_mode(struct vcpu *v, int mode);
 void hvm_init_guest_time(struct domain *d);
 void hvm_set_guest_time(struct vcpu *v, u64 guest_time);
 u64 hvm_get_guest_time_fixed(struct vcpu *v, u64 at_tsc);
-- 
1.8.1.4