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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v3 2/2] x86/PCI: Intercept accesses to RO MMIO from dom0s in HVM containers
Commit 9256f66c1606 ("x86/PCI: intercept all PV Dom0 MMCFG writes")
added intercepts for writes to RO MMCFG space from PV dom0.
Similar functionality, including access to RO non-MMCFG addresses, is
needed by dom0s in HVM containers (such as PVH and, in the future,
HVMlite).
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
---
xen/arch/x86/hvm/emulate.c | 46 +++++++++++++++++++++++++
xen/arch/x86/hvm/hvm.c | 8 ++++
xen/arch/x86/mm.c | 58 ++++++++++---------------------
xen/arch/x86/x86_64/mmconfig_64.c | 10 +++++
xen/arch/x86/x86_emulate/x86_emulate.c | 10 +++++
xen/arch/x86/x86_emulate/x86_emulate.h | 12 ++++++
xen/include/asm-x86/hvm/emulate.h | 1 +
xen/include/asm-x86/mm.h | 17 +++++++++
xen/include/asm-x86/pci.h | 3 ++
9 files changed, 126 insertions(+), 39 deletions(-)
diff --git a/xen/arch/x86/hvm/emulate.c b/xen/arch/x86/hvm/emulate.c
index e1017b5..f5dd1f8 100644
--- a/xen/arch/x86/hvm/emulate.c
+++ b/xen/arch/x86/hvm/emulate.c
@@ -1778,6 +1778,52 @@ int hvm_emulate_one_no_write(
return _hvm_emulate_one(hvmemul_ctxt, &hvm_emulate_ops_no_write);
}
+int hvm_emulate_one_mmio(unsigned long mfn, unsigned long gla)
+{
+ static const struct x86_emulate_ops hvm_intercept_ops_mmcfg = {
+ .read = x86emul_unhandleable_rw,
+ .insn_fetch = hvmemul_insn_fetch,
+ .write = mmcfg_intercept_write,
+ };
+ static const struct x86_emulate_ops hvm_ro_emulate_ops_mmio = {
+ .read = x86emul_unhandleable_rw,
+ .insn_fetch = hvmemul_insn_fetch,
+ .write = mmio_ro_emulated_write
+ };
+ struct mmio_ro_emulate_ctxt mmio_ro_ctxt = { .cr2 = gla };
+ struct hvm_emulate_ctxt ctxt;
+ const struct x86_emulate_ops *ops;
+ unsigned int seg, bdf;
+ int rc;
+
+ if ( pci_ro_mmcfg_decode(mfn, &seg, &bdf) )
+ {
+ mmio_ro_ctxt.seg = seg;
+ mmio_ro_ctxt.bdf = bdf;
+ ops = &hvm_intercept_ops_mmcfg;
+ }
+ else
+ ops = &hvm_ro_emulate_ops_mmio;
+
+ hvm_emulate_prepare(&ctxt, guest_cpu_user_regs());
+ ctxt.ctxt.data = &mmio_ro_ctxt;
+ rc = _hvm_emulate_one(&ctxt, ops);
+ 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..ed9bbc9 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -3115,6 +3115,14 @@ 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 &&
+ (hvm_emulate_one_mmio(mfn_x(mfn), 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..7323d9d 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 = x86emul_unhandleable_rw,
.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 = x86emul_unhandleable_rw,
.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. */
@@ -5331,14 +5313,14 @@ 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;
/* Attempt to read the PTE that maps the VA being accessed. */
@@ -5363,12 +5345,10 @@ int mmio_ro_do_page_fault(struct vcpu *v, unsigned long
addr,
if ( !rangeset_contains_singleton(mmio_ro_ranges, mfn) )
return 0;
- 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);
+ if ( pci_ro_mmcfg_decode(mfn, &mmio_ro_ctxt.seg, &mmio_ro_ctxt.bdf) )
+ 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_64/mmconfig_64.c
b/xen/arch/x86/x86_64/mmconfig_64.c
index 1f9a996..7618d67 100644
--- a/xen/arch/x86/x86_64/mmconfig_64.c
+++ b/xen/arch/x86/x86_64/mmconfig_64.c
@@ -198,6 +198,16 @@ bool_t pci_mmcfg_decode(unsigned long mfn, unsigned int
*seg,
return 0;
}
+bool_t pci_ro_mmcfg_decode(unsigned long mfn, unsigned int *seg,
+ unsigned int *bdf)
+{
+ const unsigned long *ro_map;
+
+ return pci_mmcfg_decode(mfn, seg, bdf) &&
+ ((ro_map = pci_get_ro_map(*seg)) == NULL ||
+ !test_bit(*bdf, ro_map));
+}
+
int __init pci_mmcfg_arch_init(void)
{
int i;
diff --git a/xen/arch/x86/x86_emulate/x86_emulate.c
b/xen/arch/x86/x86_emulate/x86_emulate.c
index f1454ce..56aef3e 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 x86emul_unhandleable_rw(
+ 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..f33c523 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 +466,13 @@ void *
decode_register(
uint8_t modrm_reg, struct cpu_user_regs *regs, int highbyte_regs);
+/* Unhandleable read, write or instruction fetch */
+int
+x86emul_unhandleable_rw(
+ 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..142d1b6 100644
--- a/xen/include/asm-x86/hvm/emulate.h
+++ b/xen/include/asm-x86/hvm/emulate.h
@@ -57,6 +57,7 @@ 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_mmio(unsigned long mfn, 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..b4075e6 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_emulated_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,
diff --git a/xen/include/asm-x86/pci.h b/xen/include/asm-x86/pci.h
index 38ace79..36801d3 100644
--- a/xen/include/asm-x86/pci.h
+++ b/xen/include/asm-x86/pci.h
@@ -23,4 +23,7 @@ int pci_msi_conf_write_intercept(struct pci_dev *, unsigned
int reg,
bool_t pci_mmcfg_decode(unsigned long mfn, unsigned int *seg,
unsigned int *bdf);
+bool_t pci_ro_mmcfg_decode(unsigned long mfn, unsigned int *seg,
+ unsigned int *bdf);
+
#endif /* __X86_PCI_H__ */
--
1.7.1
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