xen/x86: remove XENFEAT_hvm_pirqs for PVHv2 guests

PVHv2 guests, unlike HVM guests, won't have the option to route interrupts
from physical or emulated devices over event channels using PIRQs. This
applies to both DomU and Dom0 PVHv2 guests.

Introduce a new XEN_X86_EMU_USE_PIRQ to notify Xen whether a HVM guest can
route physical interrupts (even from emulated devices) over event channels,
and is thus allowed to use some of the PHYSDEV ops.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
---
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
---
Changes since v2:
 - Change local variable name to currd instead of d.
 - Use currd where it makes sense.

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 11e2b8238e929853d34625c2cd152c3253947fc7..e516b20616113bbe52d1a1e69460d37d033e1098 100644 (file)
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -4164,10 +4164,12 @@ static long hvm_memory_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 
 static long hvm_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
+    struct domain *currd = current->domain;
+
     switch ( cmd )
     {
     default:
-        if ( !is_pvh_vcpu(current) || !is_hardware_domain(current->domain) )
+        if ( !is_pvh_domain(currd) || !is_hardware_domain(currd) )
             return -ENOSYS;
         /* fall through */
     case PHYSDEVOP_map_pirq:
@@ -4175,7 +4177,9 @@ static long hvm_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
     case PHYSDEVOP_eoi:
     case PHYSDEVOP_irq_status_query:
     case PHYSDEVOP_get_free_pirq:
-        return do_physdev_op(cmd, arg);
+        return ((currd->arch.emulation_flags & XEN_X86_EMU_USE_PIRQ) ||
+               is_pvh_domain(currd)) ?
+                    do_physdev_op(cmd, arg) : -ENOSYS;
     }
 }
 
@@ -4208,17 +4212,20 @@ static long hvm_memory_op_compat32(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 static long hvm_physdev_op_compat32(
     int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
+    struct domain *d = current->domain;
+
     switch ( cmd )
     {
-        case PHYSDEVOP_map_pirq:
-        case PHYSDEVOP_unmap_pirq:
-        case PHYSDEVOP_eoi:
-        case PHYSDEVOP_irq_status_query:
-        case PHYSDEVOP_get_free_pirq:
-            return compat_physdev_op(cmd, arg);
+    case PHYSDEVOP_map_pirq:
+    case PHYSDEVOP_unmap_pirq:
+    case PHYSDEVOP_eoi:
+    case PHYSDEVOP_irq_status_query:
+    case PHYSDEVOP_get_free_pirq:
+        return (d->arch.emulation_flags & XEN_X86_EMU_USE_PIRQ) ?
+                    compat_physdev_op(cmd, arg) : -ENOSYS;
         break;
     default:
-            return -ENOSYS;
+        return -ENOSYS;
         break;
     }
 }

diff --git a/xen/arch/x86/physdev.c b/xen/arch/x86/physdev.c
index 5a4979677b0b7f7c17db869d6fe3db8ec16d57ba..0bea6e105b708c2e92487d49228ce532e7969302 100644 (file)
--- a/xen/arch/x86/physdev.c
+++ b/xen/arch/x86/physdev.c
@@ -94,7 +94,8 @@ int physdev_map_pirq(domid_t domid, int type, int *index, int *pirq_p,
     int pirq, irq, ret = 0;
     void *map_data = NULL;
 
-    if ( domid == DOMID_SELF && is_hvm_domain(d) )
+    if ( domid == DOMID_SELF && is_hvm_domain(d) &&
+         (d->arch.emulation_flags & XEN_X86_EMU_USE_PIRQ) )
     {
         /*
          * Only makes sense for vector-based callback, else HVM-IRQ logic
@@ -265,7 +266,7 @@ int physdev_unmap_pirq(domid_t domid, int pirq)
     if ( ret )
         goto free_domain;
 
-    if ( is_hvm_domain(d) )
+    if ( is_hvm_domain(d) && (d->arch.emulation_flags & XEN_X86_EMU_USE_PIRQ) )
     {
         spin_lock(&d->event_lock);
         if ( domain_pirq_to_emuirq(d, pirq) != IRQ_UNBOUND )

diff --git a/xen/common/kernel.c b/xen/common/kernel.c
index d0edb13d4bb273a845a8bac3a572d006f8f50358..a82f55fc3342e660a5b266ad57b326cef9f92cb6 100644 (file)
--- a/xen/common/kernel.c
+++ b/xen/common/kernel.c
@@ -332,7 +332,8 @@ DO(xen_version)(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
             case guest_type_hvm:
                 fi.submap |= (1U << XENFEAT_hvm_safe_pvclock) |
                              (1U << XENFEAT_hvm_callback_vector) |
-                             (1U << XENFEAT_hvm_pirqs);
+                             ((d->arch.emulation_flags & XEN_X86_EMU_USE_PIRQ) ?
+                                 (1U << XENFEAT_hvm_pirqs) : 0);
                 break;
             }
 #endif

diff --git a/xen/include/public/arch-x86/xen.h b/xen/include/public/arch-x86/xen.h
index cdd93c1c6446a92e89188c6a5132538188825d27..da6f4f28ddcc2976155b083363afdffe4cbbf32c 100644 (file)
--- a/xen/include/public/arch-x86/xen.h
+++ b/xen/include/public/arch-x86/xen.h
@@ -283,12 +283,14 @@ struct xen_arch_domainconfig {
 #define XEN_X86_EMU_IOMMU           (1U<<_XEN_X86_EMU_IOMMU)
 #define _XEN_X86_EMU_PIT            8
 #define XEN_X86_EMU_PIT             (1U<<_XEN_X86_EMU_PIT)
+#define _XEN_X86_EMU_USE_PIRQ       9
+#define XEN_X86_EMU_USE_PIRQ        (1U<<_XEN_X86_EMU_USE_PIRQ)
 
 #define XEN_X86_EMU_ALL             (XEN_X86_EMU_LAPIC | XEN_X86_EMU_HPET |  \
                                      XEN_X86_EMU_PM | XEN_X86_EMU_RTC |      \
                                      XEN_X86_EMU_IOAPIC | XEN_X86_EMU_PIC |  \
                                      XEN_X86_EMU_VGA | XEN_X86_EMU_IOMMU |   \
-                                     XEN_X86_EMU_PIT)
+                                     XEN_X86_EMU_PIT | XEN_X86_EMU_USE_PIRQ)
     uint32_t emulation_flags;
 };
 #endif