[PATCH v2] x86/hvm: unify HVM and PVH hypercall tables.

[Tim Deegan <tim@xen.org>]

Stage one of many in merging PVH and HVM code in the hypervisor.

This exposes a few new hypercalls to HVM guests, all of which were
already available to PVH ones:

 - XENMEM_memory_map / XENMEM_machine_memory_map / XENMEM_machphys_mapping:
   These are basically harmless, if a bit useless to plain HVM.

 - VCPUOP_send_nmi / VCPUOP_initialise / VCPUOP[_is]_up / VCPUOP_down
   This will eventually let HVM guests bring up APs the way PVH ones do.
   For now, the VCPUOP_initialise paths are still gated on is_pvh.
 - VCPUOP_get_physid
   Harmless.

 - __HYPERVISOR_platform_op (XSM_PRIV callers only).

 - __HYPERVISOR_mmuext_op.
   The pagetable manipulation MMUEXT ops are already denied
   (or no-ops) to paging_mode_refcounts() domains; the baseptr ones
   are already denied to paging_mode_translate() domains.
   I have restricted MMUEXT[UN]MARK_SUPER to !paging_mode_refcounts()
   domains as well, as I can see no need for them in PVH.
   I have also restricted MMUEXT_CLEAR_PAGE / MMUEXT_COPY_PAGE
   to PV domains only, as there is no need for them in HVM/PVH ones
   and they would lead to complication with sharing/paging operations.
   That leaves TLB and cache flush operations, which are OK.

 - PHYSDEVOP_* (only for hardware control domains).
   Also make ops that touch PV vcpu state (PHYSDEVOP_set_iopl and
   PHYSDEVOP_set_iobitmap) gate on is_pv rather than !is_pvh.

PVH guests can also see a few hypercalls that they couldn't before,
but which were already available to HVM guests:

 - __HYPERVISOR_set_timer_op

 - __HYPERVISOR_tmem_op

Signed-off-by: Tim Deegan <tim@xen.org>
Cc: Keir Fraser <keir@xen.org>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Mukesh Rathor <mukesh.rathor@oracle.com>
Cc: George Dunlap <george.dunlap@eu.citrix.com>
---
v2: restrict MMUEXT_CLEAR_PAGE / MMUEXT_COPY_PAGE;
    reword to correcly state that some MMUEXT ops are noops; and
    use if() rather than one-clause switch() in a few places.
---
 xen/arch/x86/hvm/hvm.c          | 129 +++++++---------------------------------
 xen/arch/x86/mm.c               |  24 ++++++++
 xen/arch/x86/physdev.c          |   4 +-
 xen/arch/x86/x86_64/compat/mm.c |   2 -
 xen/include/asm-x86/hypercall.h |  10 ++++
 5 files changed, 57 insertions(+), 112 deletions(-)

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index b69f164..57552b9 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -3844,20 +3844,12 @@ static long hvm_grant_table_op(
 
 static long hvm_memory_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
-    long rc;
+    long rc = do_memory_op(cmd, arg);
 
-    switch ( cmd & MEMOP_CMD_MASK )
-    {
-    case XENMEM_memory_map:
-    case XENMEM_machine_memory_map:
-    case XENMEM_machphys_mapping:
-        return -ENOSYS;
-    case XENMEM_decrease_reservation:
-        rc = do_memory_op(cmd, arg);
+    if ( (cmd & MEMOP_CMD_MASK) == XENMEM_decrease_reservation )
         current->domain->arch.hvm_domain.qemu_mapcache_invalidate = 1;
-        return rc;
-    }
-    return do_memory_op(cmd, arg);
+
+    return rc;
 }
 
 static long hvm_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
@@ -3865,7 +3857,7 @@ static long hvm_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
     switch ( cmd )
     {
     default:
-        if ( !is_pvh_vcpu(current) || !is_hardware_domain(current->domain) )
+        if ( !is_hardware_domain(current->domain) )
             return -ENOSYS;
         /* fall through */
     case PHYSDEVOP_map_pirq:
@@ -3877,31 +3869,6 @@ static long hvm_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
     }
 }
 
-static long hvm_vcpu_op(
-    int cmd, int vcpuid, XEN_GUEST_HANDLE_PARAM(void) arg)
-{
-    long rc;
-
-    switch ( cmd )
-    {
-    case VCPUOP_register_runstate_memory_area:
-    case VCPUOP_get_runstate_info:
-    case VCPUOP_set_periodic_timer:
-    case VCPUOP_stop_periodic_timer:
-    case VCPUOP_set_singleshot_timer:
-    case VCPUOP_stop_singleshot_timer:
-    case VCPUOP_register_vcpu_info:
-    case VCPUOP_register_vcpu_time_memory_area:
-        rc = do_vcpu_op(cmd, vcpuid, arg);
-        break;
-    default:
-        rc = -ENOSYS;
-        break;
-    }
-
-    return rc;
-}
-
 typedef unsigned long hvm_hypercall_t(
     unsigned long, unsigned long, unsigned long, unsigned long, unsigned long,
     unsigned long);
@@ -3920,43 +3887,10 @@ static long hvm_grant_table_op_compat32(unsigned int cmd,
 
 static long hvm_memory_op_compat32(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
-    int rc;
+    int rc = compat_memory_op(cmd, arg);
 
-    switch ( cmd & MEMOP_CMD_MASK )
-    {
-    case XENMEM_memory_map:
-    case XENMEM_machine_memory_map:
-    case XENMEM_machphys_mapping:
-        return -ENOSYS;
-    case XENMEM_decrease_reservation:
-        rc = compat_memory_op(cmd, arg);
+    if ( (cmd & MEMOP_CMD_MASK) == XENMEM_decrease_reservation )
         current->domain->arch.hvm_domain.qemu_mapcache_invalidate = 1;
-        return rc;
-    }
-    return compat_memory_op(cmd, arg);
-}
-
-static long hvm_vcpu_op_compat32(
-    int cmd, int vcpuid, XEN_GUEST_HANDLE_PARAM(void) arg)
-{
-    long rc;
-
-    switch ( cmd )
-    {
-    case VCPUOP_register_runstate_memory_area:
-    case VCPUOP_get_runstate_info:
-    case VCPUOP_set_periodic_timer:
-    case VCPUOP_stop_periodic_timer:
-    case VCPUOP_set_singleshot_timer:
-    case VCPUOP_stop_singleshot_timer:
-    case VCPUOP_register_vcpu_info:
-    case VCPUOP_register_vcpu_time_memory_area:
-        rc = compat_vcpu_op(cmd, vcpuid, arg);
-        break;
-    default:
-        rc = -ENOSYS;
-        break;
-    }
 
     return rc;
 }
@@ -3966,27 +3900,29 @@ static long hvm_physdev_op_compat32(
 {
     switch ( cmd )
     {
+    default:
+        if ( !is_hardware_domain(current->domain) )
+            return -ENOSYS;
+        /* fall through */
         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);
-        break;
-    default:
-            return -ENOSYS;
-        break;
     }
 }
 
 static hvm_hypercall_t *const hvm_hypercall64_table[NR_hypercalls] = {
     [ __HYPERVISOR_memory_op ] = (hvm_hypercall_t *)hvm_memory_op,
     [ __HYPERVISOR_grant_table_op ] = (hvm_hypercall_t *)hvm_grant_table_op,
-    [ __HYPERVISOR_vcpu_op ] = (hvm_hypercall_t *)hvm_vcpu_op,
     [ __HYPERVISOR_physdev_op ] = (hvm_hypercall_t *)hvm_physdev_op,
+    HYPERCALL(platform_op),
     HYPERCALL(xen_version),
     HYPERCALL(console_io),
     HYPERCALL(event_channel_op),
+    HYPERCALL(vcpu_op),
+    HYPERCALL(mmuext_op),
     HYPERCALL(sched_op),
     HYPERCALL(set_timer_op),
     HYPERCALL(xsm_op),
@@ -4002,11 +3938,13 @@ static hvm_hypercall_t *const hvm_hypercall64_table[NR_hypercalls] = {
 static hvm_hypercall_t *const hvm_hypercall32_table[NR_hypercalls] = {
     [ __HYPERVISOR_memory_op ] = (hvm_hypercall_t *)hvm_memory_op_compat32,
     [ __HYPERVISOR_grant_table_op ] = (hvm_hypercall_t *)hvm_grant_table_op_compat32,
-    [ __HYPERVISOR_vcpu_op ] = (hvm_hypercall_t *)hvm_vcpu_op_compat32,
     [ __HYPERVISOR_physdev_op ] = (hvm_hypercall_t *)hvm_physdev_op_compat32,
+    HYPERCALL(platform_op),
     COMPAT_CALL(xen_version),
     HYPERCALL(console_io),
     HYPERCALL(event_channel_op),
+    COMPAT_CALL(vcpu_op),
+    COMPAT_CALL(mmuext_op),
     COMPAT_CALL(sched_op),
     COMPAT_CALL(set_timer_op),
     HYPERCALL(xsm_op),
@@ -4016,24 +3954,6 @@ static hvm_hypercall_t *const hvm_hypercall32_table[NR_hypercalls] = {
     HYPERCALL(tmem_op)
 };
 
-/* PVH 32bitfixme. */
-static hvm_hypercall_t *const pvh_hypercall64_table[NR_hypercalls] = {
-    HYPERCALL(platform_op),
-    HYPERCALL(memory_op),
-    HYPERCALL(xen_version),
-    HYPERCALL(console_io),
-    [ __HYPERVISOR_grant_table_op ]  = (hvm_hypercall_t *)hvm_grant_table_op,
-    HYPERCALL(vcpu_op),
-    HYPERCALL(mmuext_op),
-    HYPERCALL(xsm_op),
-    HYPERCALL(sched_op),
-    HYPERCALL(event_channel_op),
-    [ __HYPERVISOR_physdev_op ]      = (hvm_hypercall_t *)hvm_physdev_op,
-    HYPERCALL(hvm_op),
-    HYPERCALL(sysctl),
-    HYPERCALL(domctl)
-};
-
 int hvm_do_hypercall(struct cpu_user_regs *regs)
 {
     struct vcpu *curr = current;
@@ -4060,9 +3980,7 @@ int hvm_do_hypercall(struct cpu_user_regs *regs)
     if ( (eax & 0x80000000) && is_viridian_domain(curr->domain) )
         return viridian_hypercall(regs);
 
-    if ( (eax >= NR_hypercalls) ||
-         (is_pvh_vcpu(curr) ? !pvh_hypercall64_table[eax]
-                            : !hvm_hypercall32_table[eax]) )
+    if ( (eax >= NR_hypercalls) || !hvm_hypercall32_table[eax] )
     {
         regs->eax = -ENOSYS;
         return HVM_HCALL_completed;
@@ -4077,14 +3995,9 @@ int hvm_do_hypercall(struct cpu_user_regs *regs)
                     regs->r10, regs->r8, regs->r9);
 
         curr->arch.hvm_vcpu.hcall_64bit = 1;
-        if ( is_pvh_vcpu(curr) )
-            regs->rax = pvh_hypercall64_table[eax](regs->rdi, regs->rsi,
-                                                   regs->rdx, regs->r10,
-                                                   regs->r8, regs->r9);
-        else
-            regs->rax = hvm_hypercall64_table[eax](regs->rdi, regs->rsi,
-                                                   regs->rdx, regs->r10,
-                                                   regs->r8, regs->r9);
+        regs->rax = hvm_hypercall64_table[eax](regs->rdi, regs->rsi,
+                                               regs->rdx, regs->r10,
+                                               regs->r8, regs->r9);
         curr->arch.hvm_vcpu.hcall_64bit = 0;
     }
     else
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 1a8a5e0..a263d26 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -3253,6 +3253,12 @@ long do_mmuext_op(
         case MMUEXT_CLEAR_PAGE: {
             struct page_info *page;
 
+            if ( !is_pv_vcpu(current) )
+            {
+                okay = 0;
+                break;
+            }
+
             page = get_page_from_gfn(d, op.arg1.mfn, NULL, P2M_ALLOC);
             if ( !page || !get_page_type(page, PGT_writable_page) )
             {
@@ -3276,6 +3282,12 @@ long do_mmuext_op(
         {
             struct page_info *src_page, *dst_page;
 
+            if ( !is_pv_vcpu(current) )
+            {
+                okay = 0;
+                break;
+            }
+
             src_page = get_page_from_gfn(d, op.arg2.src_mfn, NULL, P2M_ALLOC);
             if ( unlikely(!src_page) )
             {
@@ -3310,6 +3322,12 @@ long do_mmuext_op(
             unsigned long mfn;
             struct spage_info *spage;
 
+            if ( paging_mode_refcounts(pg_owner) )
+            {
+                okay = 0;
+                break;
+            }
+
             mfn = op.arg1.mfn;
             if ( mfn & (L1_PAGETABLE_ENTRIES-1) )
             {
@@ -3336,6 +3354,12 @@ long do_mmuext_op(
             unsigned long mfn;
             struct spage_info *spage;
 
+            if ( paging_mode_refcounts(pg_owner) )
+            {
+                okay = 0;
+                break;
+            }
+
             mfn = op.arg1.mfn;
             if ( mfn & (L1_PAGETABLE_ENTRIES-1) )
             {
diff --git a/xen/arch/x86/physdev.c b/xen/arch/x86/physdev.c
index f178315..a2d2b96 100644
--- a/xen/arch/x86/physdev.c
+++ b/xen/arch/x86/physdev.c
@@ -520,7 +520,7 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
         struct physdev_set_iopl set_iopl;
 
         ret = -ENOSYS;
-        if ( is_pvh_vcpu(current) )
+        if ( !is_pv_vcpu(current) )
             break;
 
         ret = -EFAULT;
@@ -538,7 +538,7 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
         struct physdev_set_iobitmap set_iobitmap;
 
         ret = -ENOSYS;
-        if ( is_pvh_vcpu(current) )
+        if ( !is_pv_vcpu(current) )
             break;
 
         ret = -EFAULT;
diff --git a/xen/arch/x86/x86_64/compat/mm.c b/xen/arch/x86/x86_64/compat/mm.c
index 69c6195..3fa90aa 100644
--- a/xen/arch/x86/x86_64/compat/mm.c
+++ b/xen/arch/x86/x86_64/compat/mm.c
@@ -236,8 +236,6 @@ int compat_update_va_mapping_otherdomain(unsigned long va, u32 lo, u32 hi,
     return do_update_va_mapping_otherdomain(va, lo | ((u64)hi << 32), flags, domid);
 }
 
-DEFINE_XEN_GUEST_HANDLE(mmuext_op_compat_t);
-
 int compat_mmuext_op(XEN_GUEST_HANDLE_PARAM(mmuext_op_compat_t) cmp_uops,
                      unsigned int count,
                      XEN_GUEST_HANDLE_PARAM(uint) pdone,
diff --git a/xen/include/asm-x86/hypercall.h b/xen/include/asm-x86/hypercall.h
index afa8ba9..cee8817 100644
--- a/xen/include/asm-x86/hypercall.h
+++ b/xen/include/asm-x86/hypercall.h
@@ -8,6 +8,7 @@
 #include <public/physdev.h>
 #include <public/arch-x86/xen-mca.h> /* for do_mca */
 #include <xen/types.h>
+#include <compat/memory.h>
 
 /*
  * Both do_mmuext_op() and do_mmu_update():
@@ -110,4 +111,13 @@ extern int
 arch_compat_vcpu_op(
     int cmd, struct vcpu *v, XEN_GUEST_HANDLE_PARAM(void) arg);
 
+DEFINE_XEN_GUEST_HANDLE(mmuext_op_compat_t);
+
+extern int
+compat_mmuext_op(
+    XEN_GUEST_HANDLE_PARAM(mmuext_op_compat_t) cmp_uops,
+    unsigned int count,
+    XEN_GUEST_HANDLE_PARAM(uint) pdone,
+    unsigned int foreigndom);
+
 #endif /* __ASM_X86_HYPERCALL_H__ */
-- 
1.8.5.2