x86/pvh: use a custom IO bitmap for PVH hardware domains

Since a PVH hardware domain has access to the physical hardware create a
custom more permissive IO bitmap. The permissions set on the bitmap are
populated based on the contents of the ioports rangeset.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>

xen/arch/x86/hvm/hvm.c

@@ -77,9 +77,13 @@ integer_param("hvm_debug", opt_hvm_debug_level);
 
 struct hvm_function_table hvm_funcs __read_mostly;
 
-/* I/O permission bitmap is globally shared by all HVM guests. */
+/*
+ * The I/O permission bitmap is globally shared by all HVM guests except
+ * the hardware domain which needs a more permissive one.
+ */
+#define HVM_IOBITMAP_SIZE (3 * PAGE_SIZE)
 unsigned long __attribute__ ((__section__ (".bss.page_aligned")))
-    hvm_io_bitmap[3*PAGE_SIZE/BYTES_PER_LONG];
+    hvm_io_bitmap[HVM_IOBITMAP_SIZE / BYTES_PER_LONG];
 
 /* Xen command-line option to enable HAP */
 static bool_t __initdata opt_hap_enabled = 1;
@@ -1461,6 +1465,20 @@ int hvm_domain_initialise(struct domain *d)
         goto fail1;
     d->arch.hvm_domain.io_handler->num_slot = 0;
 
+    /* Set the default IO Bitmap. */
+    if ( is_hardware_domain(d) )
+    {
+        d->arch.hvm_domain.io_bitmap = _xmalloc(HVM_IOBITMAP_SIZE, PAGE_SIZE);
+        if ( d->arch.hvm_domain.io_bitmap == NULL )
+        {
+            rc = -ENOMEM;
+            goto fail1;
+        }
+        memset(d->arch.hvm_domain.io_bitmap, ~0, HVM_IOBITMAP_SIZE);
+    }
+    else
+        d->arch.hvm_domain.io_bitmap = hvm_io_bitmap;
+
     if ( is_pvh_domain(d) )
     {
         register_portio_handler(d, 0, 0x10003, handle_pvh_io);
@@ -1496,6 +1514,8 @@ int hvm_domain_initialise(struct domain *d)
     stdvga_deinit(d);
     vioapic_deinit(d);
  fail1:
+    if ( is_hardware_domain(d) )
+        xfree(d->arch.hvm_domain.io_bitmap);
     xfree(d->arch.hvm_domain.io_handler);
     xfree(d->arch.hvm_domain.params);
  fail0:

xen/arch/x86/hvm/svm/vmcb.c

@@ -118,7 +118,7 @@ static int construct_vmcb(struct vcpu *v)
         svm_disable_intercept_for_msr(v, MSR_AMD64_LWP_CBADDR);
 
     vmcb->_msrpm_base_pa = (u64)virt_to_maddr(arch_svm->msrpm);
-    vmcb->_iopm_base_pa  = (u64)virt_to_maddr(hvm_io_bitmap);
+    vmcb->_iopm_base_pa = __pa(v->domain->arch.hvm_domain.io_bitmap);
 
     /* Virtualise EFLAGS.IF and LAPIC TPR (CR8). */
     vmcb->_vintr.fields.intr_masking = 1;

xen/arch/x86/hvm/vmx/vmcs.c

@@ -1032,8 +1032,8 @@ static int construct_vmcs(struct vcpu *v)
     }
 
     /* I/O access bitmap. */
-    __vmwrite(IO_BITMAP_A, virt_to_maddr((char *)hvm_io_bitmap + 0));
+    __vmwrite(IO_BITMAP_A, __pa(d->arch.hvm_domain.io_bitmap));
-    __vmwrite(IO_BITMAP_B, virt_to_maddr((char *)hvm_io_bitmap + PAGE_SIZE));
+    __vmwrite(IO_BITMAP_B, __pa(d->arch.hvm_domain.io_bitmap) + PAGE_SIZE);
 
     if ( cpu_has_vmx_virtual_intr_delivery )
     {

xen/arch/x86/setup.c

@@ -1446,6 +1446,8 @@ void __init noreturn __start_xen(unsigned long mbi_p)
 
     dmi_end_boot();
 
+    setup_io_bitmap(dom0);
+
     system_state = SYS_STATE_active;
 
     domain_unpause_by_systemcontroller(dom0);
@@ -1509,6 +1511,32 @@ int __hwdom_init xen_in_range(unsigned long mfn)
     return 0;
 }
 
+static int __hwdom_init io_bitmap_cb(unsigned long s, unsigned long e,
+                                     void *ctx)
+{
+    struct domain *d = ctx;
+    unsigned int i;
+
+    ASSERT(e <= INT_MAX);
+    for ( i = s; i <= e; i++ )
+        __clear_bit(i, d->arch.hvm_domain.io_bitmap);
+
+    return 0;
+}
+
+void __hwdom_init setup_io_bitmap(struct domain *d)
+{
+    int rc;
+
+    if ( has_hvm_container_domain(d) )
+    {
+        bitmap_fill(d->arch.hvm_domain.io_bitmap, 0x10000);
+        rc = rangeset_report_ranges(d->arch.ioport_caps, 0, 0x10000,
+                                    io_bitmap_cb, d);
+        BUG_ON(rc);
+    }
+}
+
 /*
  * Local variables:
  * mode: C

xen/common/domain.c

@@ -42,6 +42,7 @@
 #include <xsm/xsm.h>
 #include <xen/trace.h>
 #include <xen/tmem.h>
+#include <asm/setup.h>
 
 /* Linux config option: propageted to domain0 */
 /* xen_processor_pmbits: xen control Cx, Px, ... */
@@ -219,6 +220,8 @@ static int late_hwdom_init(struct domain *d)
     rangeset_swap(d->iomem_caps, dom0->iomem_caps);
 #ifdef CONFIG_X86
     rangeset_swap(d->arch.ioport_caps, dom0->arch.ioport_caps);
+    setup_io_bitmap(d);
+    setup_io_bitmap(dom0);
 #endif
 
     rcu_unlock_domain(dom0);

xen/include/asm-x86/hvm/domain.h

@@ -141,6 +141,8 @@ struct hvm_domain {
      */
     uint64_t sync_tsc;
 
+    unsigned long *io_bitmap;
+
     union {
         struct vmx_domain vmx;
         struct svm_domain svm;

xen/include/asm-x86/setup.h

@@ -32,6 +32,7 @@ int construct_dom0(
     module_t *initrd,
     void *(*bootstrap_map)(const module_t *),
     char *cmdline);
+void setup_io_bitmap(struct domain *d);
 
 unsigned long initial_images_nrpages(nodeid_t node);
 void discard_initial_images(void);