diff mbox

[v2,2/2] x86/PCI: Intercept Dom0 MMCFG from dom0s in HVM containers

Message ID 1450383771-3636-3-git-send-email-boris.ostrovsky@oracle.com (mailing list archive)
State New, archived
Headers show

Commit Message

Boris Ostrovsky Dec. 17, 2015, 8:22 p.m. UTC
Commit 9256f66c1606 ("x86/PCI: intercept all PV Dom0 MMCFG writes")
added intercepts for writes to RO MMCFG space from PV dom0.

Similar functionality is needed by dom0s in HVM containers (such as
PVH and, in the future, HVMlite).

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
 xen/arch/x86/hvm/emulate.c             |   34 ++++++++++++++++++++
 xen/arch/x86/hvm/hvm.c                 |   15 +++++++++
 xen/arch/x86/mm.c                      |   53 +++++++++++---------------------
 xen/arch/x86/x86_emulate/x86_emulate.c |   10 ++++++
 xen/arch/x86/x86_emulate/x86_emulate.h |   13 ++++++++
 xen/include/asm-x86/hvm/emulate.h      |    4 ++
 xen/include/asm-x86/mm.h               |   17 ++++++++++
 7 files changed, 111 insertions(+), 35 deletions(-)

Comments

Jan Beulich Dec. 18, 2015, 10:28 a.m. UTC | #1
>>> On 17.12.15 at 21:22, <boris.ostrovsky@oracle.com> wrote:
> Commit 9256f66c1606 ("x86/PCI: intercept all PV Dom0 MMCFG writes")
> added intercepts for writes to RO MMCFG space from PV dom0.
> 
> Similar functionality is needed by dom0s in HVM containers (such as
> PVH and, in the future, HVMlite).
> 
> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

Looks okay leaving aside the question of r/o device handling. A few
minor remarks:

> @@ -463,4 +466,14 @@ void *
>  decode_register(
>      uint8_t modrm_reg, struct cpu_user_regs *regs, int highbyte_regs);
>  
> +/* Unhadleable read, write or instruction fetch */

Unhandleable

> +int
> +unhandleable_rwx(

x86emul_unhandleable_rwx() or some such, making it clear what
component it belongs to. I also doubt the x here really makes much
sense - the insn_fetch field can't usefully point to that function.

> +    enum x86_segment seg,
> +    unsigned long offset,
> +    void *p_data,
> +    unsigned int bytes,
> +    struct x86_emulate_ctxt *ctxt);
> +
> +
>  #endif /* __X86_EMULATE_H__ */

One blank line only please.

Jan
diff mbox

Patch

diff --git a/xen/arch/x86/hvm/emulate.c b/xen/arch/x86/hvm/emulate.c
index e1017b5..6f6ec61 100644
--- a/xen/arch/x86/hvm/emulate.c
+++ b/xen/arch/x86/hvm/emulate.c
@@ -1778,6 +1778,40 @@  int hvm_emulate_one_no_write(
     return _hvm_emulate_one(hvmemul_ctxt, &hvm_emulate_ops_no_write);
 }
 
+int hvm_emulate_one_mmcfg(unsigned seg, unsigned bdf, unsigned long gla)
+{
+    static const struct x86_emulate_ops hvm_emulate_ops_mmcfg = {
+        .read       = unhandleable_rwx,
+        .insn_fetch = hvmemul_insn_fetch,
+        .write      = mmcfg_intercept_write,
+    };
+    struct mmio_ro_emulate_ctxt mmio_ro_ctxt = {
+        .cr2 = gla,
+        .seg = seg,
+        .bdf = bdf
+    };
+    struct hvm_emulate_ctxt ctxt;
+    int rc;
+
+    hvm_emulate_prepare(&ctxt, guest_cpu_user_regs());
+    ctxt.ctxt.data = &mmio_ro_ctxt;
+    rc = _hvm_emulate_one(&ctxt, &hvm_emulate_ops_mmcfg);
+    switch ( rc )
+    {
+    case X86EMUL_UNHANDLEABLE:
+        hvm_dump_emulation_state(XENLOG_G_WARNING "MMCFG", &ctxt);
+        break;
+    case X86EMUL_EXCEPTION:
+        if ( ctxt.exn_pending )
+            hvm_inject_trap(&ctxt.trap);
+        /* fallthrough */
+    default:
+        hvm_emulate_writeback(&ctxt);
+    }
+
+    return rc;
+}
+
 void hvm_mem_access_emulate_one(enum emul_kind kind, unsigned int trapnr,
     unsigned int errcode)
 {
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 08cef1f..7cc057b 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -3115,6 +3115,21 @@  int hvm_hap_nested_page_fault(paddr_t gpa, unsigned long gla,
         goto out_put_gfn;
     }
 
+    if ( (p2mt == p2m_mmio_direct) && is_hardware_domain(currd) &&
+         npfec.write_access && npfec.present )
+    {
+        unsigned int seg, bdf;
+        const unsigned long *ro_map;
+
+        if ( pci_mmcfg_decode(mfn_x(mfn), &seg, &bdf) &&
+             ((ro_map = pci_get_ro_map(seg)) == NULL || !test_bit(bdf, ro_map)) &&
+             (hvm_emulate_one_mmcfg(seg, bdf, gla) == X86EMUL_OKAY) )
+        {
+            rc = 1;
+            goto out_put_gfn;
+        }
+    }
+
     /* If we fell through, the vcpu will retry now that access restrictions have
      * been removed. It may fault again if the p2m entry type still requires so.
      * Otherwise, this is an error condition. */
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 92df36f..a7767f8 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -5243,31 +5243,14 @@  int ptwr_do_page_fault(struct vcpu *v, unsigned long addr,
  * fault handling for read-only MMIO pages
  */
 
-struct mmio_ro_emulate_ctxt {
-    struct x86_emulate_ctxt ctxt;
-    unsigned long cr2;
-    unsigned int seg, bdf;
-};
-
-static int mmio_ro_emulated_read(
-    enum x86_segment seg,
-    unsigned long offset,
-    void *p_data,
-    unsigned int bytes,
-    struct x86_emulate_ctxt *ctxt)
-{
-    return X86EMUL_UNHANDLEABLE;
-}
-
-static int mmio_ro_emulated_write(
+int mmio_ro_emulated_write(
     enum x86_segment seg,
     unsigned long offset,
     void *p_data,
     unsigned int bytes,
     struct x86_emulate_ctxt *ctxt)
 {
-    struct mmio_ro_emulate_ctxt *mmio_ro_ctxt =
-        container_of(ctxt, struct mmio_ro_emulate_ctxt, ctxt);
+    struct mmio_ro_emulate_ctxt *mmio_ro_ctxt = ctxt->data;
 
     /* Only allow naturally-aligned stores at the original %cr2 address. */
     if ( ((bytes | offset) & (bytes - 1)) || offset != mmio_ro_ctxt->cr2 )
@@ -5281,20 +5264,19 @@  static int mmio_ro_emulated_write(
 }
 
 static const struct x86_emulate_ops mmio_ro_emulate_ops = {
-    .read       = mmio_ro_emulated_read,
+    .read       = unhandleable_rwx,
     .insn_fetch = ptwr_emulated_read,
     .write      = mmio_ro_emulated_write,
 };
 
-static int mmio_intercept_write(
+int mmcfg_intercept_write(
     enum x86_segment seg,
     unsigned long offset,
     void *p_data,
     unsigned int bytes,
     struct x86_emulate_ctxt *ctxt)
 {
-    struct mmio_ro_emulate_ctxt *mmio_ctxt =
-        container_of(ctxt, struct mmio_ro_emulate_ctxt, ctxt);
+    struct mmio_ro_emulate_ctxt *mmio_ctxt = ctxt->data;
 
     /*
      * Only allow naturally-aligned stores no wider than 4 bytes to the
@@ -5303,7 +5285,7 @@  static int mmio_intercept_write(
     if ( ((bytes | offset) & (bytes - 1)) || bytes > 4 ||
          offset != mmio_ctxt->cr2 )
     {
-        MEM_LOG("mmio_intercept: bad write (cr2=%lx, addr=%lx, bytes=%u)",
+        MEM_LOG("mmcfg_intercept: bad write (cr2=%lx, addr=%lx, bytes=%u)",
                 mmio_ctxt->cr2, offset, bytes);
         return X86EMUL_UNHANDLEABLE;
     }
@@ -5318,10 +5300,10 @@  static int mmio_intercept_write(
     return X86EMUL_OKAY;
 }
 
-static const struct x86_emulate_ops mmio_intercept_ops = {
-    .read       = mmio_ro_emulated_read,
+static const struct x86_emulate_ops mmcfg_intercept_ops = {
+    .read       = unhandleable_rwx,
     .insn_fetch = ptwr_emulated_read,
-    .write      = mmio_intercept_write,
+    .write      = mmcfg_intercept_write,
 };
 
 /* Check if guest is trying to modify a r/o MMIO page. */
@@ -5331,12 +5313,13 @@  int mmio_ro_do_page_fault(struct vcpu *v, unsigned long addr,
     l1_pgentry_t pte;
     unsigned long mfn;
     unsigned int addr_size = is_pv_32bit_vcpu(v) ? 32 : BITS_PER_LONG;
-    struct mmio_ro_emulate_ctxt mmio_ro_ctxt = {
-        .ctxt.regs = regs,
-        .ctxt.addr_size = addr_size,
-        .ctxt.sp_size = addr_size,
-        .ctxt.swint_emulate = x86_swint_emulate_none,
-        .cr2 = addr
+    struct mmio_ro_emulate_ctxt mmio_ro_ctxt = { .cr2 = addr };
+    struct x86_emulate_ctxt ctxt = {
+        .regs = regs,
+        .addr_size = addr_size,
+        .sp_size = addr_size,
+        .swint_emulate = x86_swint_emulate_none,
+        .data = &mmio_ro_ctxt
     };
     const unsigned long *ro_map;
     int rc;
@@ -5366,9 +5349,9 @@  int mmio_ro_do_page_fault(struct vcpu *v, unsigned long addr,
     if ( pci_mmcfg_decode(mfn, &mmio_ro_ctxt.seg, &mmio_ro_ctxt.bdf) &&
          ((ro_map = pci_get_ro_map(mmio_ro_ctxt.seg)) == NULL ||
           !test_bit(mmio_ro_ctxt.bdf, ro_map)) )
-        rc = x86_emulate(&mmio_ro_ctxt.ctxt, &mmio_intercept_ops);
+        rc = x86_emulate(&ctxt, &mmcfg_intercept_ops);
     else
-        rc = x86_emulate(&mmio_ro_ctxt.ctxt, &mmio_ro_emulate_ops);
+        rc = x86_emulate(&ctxt, &mmio_ro_emulate_ops);
 
     return rc != X86EMUL_UNHANDLEABLE ? EXCRET_fault_fixed : 0;
 }
diff --git a/xen/arch/x86/x86_emulate/x86_emulate.c b/xen/arch/x86/x86_emulate/x86_emulate.c
index f1454ce..dde37ba 100644
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -1444,6 +1444,16 @@  static int inject_swint(enum x86_swint_type type,
     return ops->inject_hw_exception(fault_type, error_code, ctxt);
 }
 
+int unhandleable_rwx(
+    enum x86_segment seg,
+    unsigned long offset,
+    void *p_data,
+    unsigned int bytes,
+    struct x86_emulate_ctxt *ctxt)
+{
+    return X86EMUL_UNHANDLEABLE;
+}
+
 int
 x86_emulate(
     struct x86_emulate_ctxt *ctxt,
diff --git a/xen/arch/x86/x86_emulate/x86_emulate.h b/xen/arch/x86/x86_emulate/x86_emulate.h
index cfac09b..d1754b9 100644
--- a/xen/arch/x86/x86_emulate/x86_emulate.h
+++ b/xen/arch/x86/x86_emulate/x86_emulate.h
@@ -430,6 +430,9 @@  struct x86_emulate_ctxt
         } flags;
         uint8_t byte;
     } retire;
+
+    /* Caller data that can be used by x86_emulate_ops' routines. */
+    void *data;
 };
 
 struct x86_emulate_stub {
@@ -463,4 +466,14 @@  void *
 decode_register(
     uint8_t modrm_reg, struct cpu_user_regs *regs, int highbyte_regs);
 
+/* Unhadleable read, write or instruction fetch */
+int
+unhandleable_rwx(
+    enum x86_segment seg,
+    unsigned long offset,
+    void *p_data,
+    unsigned int bytes,
+    struct x86_emulate_ctxt *ctxt);
+
+
 #endif /* __X86_EMULATE_H__ */
diff --git a/xen/include/asm-x86/hvm/emulate.h b/xen/include/asm-x86/hvm/emulate.h
index 49134b5..2f39ff8 100644
--- a/xen/include/asm-x86/hvm/emulate.h
+++ b/xen/include/asm-x86/hvm/emulate.h
@@ -57,6 +57,10 @@  void hvm_emulate_writeback(
 struct segment_register *hvmemul_get_seg_reg(
     enum x86_segment seg,
     struct hvm_emulate_ctxt *hvmemul_ctxt);
+int hvm_emulate_one_mmcfg(
+    unsigned int seg,
+    unsigned int bdf,
+    unsigned long gla);
 
 int hvmemul_do_pio_buffer(uint16_t port,
                           unsigned int size,
diff --git a/xen/include/asm-x86/mm.h b/xen/include/asm-x86/mm.h
index 67b34c6..773ba5d 100644
--- a/xen/include/asm-x86/mm.h
+++ b/xen/include/asm-x86/mm.h
@@ -7,6 +7,7 @@ 
 #include <xen/spinlock.h>
 #include <asm/io.h>
 #include <asm/uaccess.h>
+#include <asm/x86_emulate.h>
 
 /*
  * Per-page-frame information.
@@ -488,6 +489,22 @@  void memguard_unguard_range(void *p, unsigned long l);
 void memguard_guard_stack(void *p);
 void memguard_unguard_stack(void *p);
 
+struct mmio_ro_emulate_ctxt {
+        unsigned long cr2;
+        unsigned int seg, bdf;
+};
+
+extern int mmio_ro_emulate_write(enum x86_segment seg,
+                                 unsigned long offset,
+                                 void *p_data,
+                                 unsigned int bytes,
+                                 struct x86_emulate_ctxt *ctxt);
+extern int mmcfg_intercept_write(enum x86_segment seg,
+                                 unsigned long offset,
+                                 void *p_data,
+                                 unsigned int bytes,
+                                 struct x86_emulate_ctxt *ctxt);
+
 int  ptwr_do_page_fault(struct vcpu *, unsigned long,
                         struct cpu_user_regs *);
 int  mmio_ro_do_page_fault(struct vcpu *, unsigned long,