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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v3 12/21] x86/mm: split out readonly MMIO emulation code
Move the code to pv/emul-mmio-op.c. Fix coding style issues while
moving.
Note that mmio_ro_emulated_write is needed by both PV and HVM, so it
is left in x86/mm.c.
Signed-off-by: Wei Liu <wei.liu2@xxxxxxxxxx>
---
xen/arch/x86/mm.c | 129 --------------------------------
xen/arch/x86/pv/Makefile | 1 +
xen/arch/x86/pv/emul-mmio-op.c | 166 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 167 insertions(+), 129 deletions(-)
create mode 100644 xen/arch/x86/pv/emul-mmio-op.c
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 548780aba6..26ad4a2e3b 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -5013,11 +5013,6 @@ long arch_memory_op(unsigned long cmd,
XEN_GUEST_HANDLE_PARAM(void) arg)
return 0;
}
-
-/*************************
- * fault handling for read-only MMIO pages
- */
-
int mmio_ro_emulated_write(
enum x86_segment seg,
unsigned long offset,
@@ -5039,130 +5034,6 @@ int mmio_ro_emulated_write(
return X86EMUL_OKAY;
}
-static const struct x86_emulate_ops mmio_ro_emulate_ops = {
- .read = x86emul_unhandleable_rw,
- .insn_fetch = pv_emul_ptwr_read,
- .write = mmio_ro_emulated_write,
- .validate = pv_emul_is_mem_write,
- .cpuid = pv_emul_cpuid,
-};
-
-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 = ctxt->data;
-
- /*
- * Only allow naturally-aligned stores no wider than 4 bytes to the
- * original %cr2 address.
- */
- if ( ((bytes | offset) & (bytes - 1)) || bytes > 4 || !bytes ||
- offset != mmio_ctxt->cr2 )
- {
- gdprintk(XENLOG_WARNING, "bad write (cr2=%lx, addr=%lx, bytes=%u)\n",
- mmio_ctxt->cr2, offset, bytes);
- return X86EMUL_UNHANDLEABLE;
- }
-
- offset &= 0xfff;
- if ( pci_conf_write_intercept(mmio_ctxt->seg, mmio_ctxt->bdf,
- offset, bytes, p_data) >= 0 )
- pci_mmcfg_write(mmio_ctxt->seg, PCI_BUS(mmio_ctxt->bdf),
- PCI_DEVFN2(mmio_ctxt->bdf), offset, bytes,
- *(uint32_t *)p_data);
-
- return X86EMUL_OKAY;
-}
-
-static const struct x86_emulate_ops mmcfg_intercept_ops = {
- .read = x86emul_unhandleable_rw,
- .insn_fetch = pv_emul_ptwr_read,
- .write = mmcfg_intercept_write,
- .validate = pv_emul_is_mem_write,
- .cpuid = pv_emul_cpuid,
-};
-
-/* Check if guest is trying to modify a r/o MMIO page. */
-int mmio_ro_do_page_fault(struct vcpu *v, unsigned long addr,
- struct cpu_user_regs *regs)
-{
- 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 = { .cr2 = addr };
- struct x86_emulate_ctxt ctxt = {
- .regs = regs,
- .vendor = v->domain->arch.cpuid->x86_vendor,
- .addr_size = addr_size,
- .sp_size = addr_size,
- .lma = !is_pv_32bit_vcpu(v),
- .data = &mmio_ro_ctxt,
- };
- int rc;
-
- /* Attempt to read the PTE that maps the VA being accessed. */
- pv_get_guest_eff_l1e(addr, &pte);
-
- /* We are looking only for read-only mappings of MMIO pages. */
- if ( ((l1e_get_flags(pte) & (_PAGE_PRESENT|_PAGE_RW)) != _PAGE_PRESENT) )
- return 0;
-
- mfn = l1e_get_pfn(pte);
- if ( mfn_valid(_mfn(mfn)) )
- {
- struct page_info *page = mfn_to_page(mfn);
- struct domain *owner = page_get_owner_and_reference(page);
-
- if ( owner )
- put_page(page);
- if ( owner != dom_io )
- return 0;
- }
-
- if ( !rangeset_contains_singleton(mmio_ro_ranges, mfn) )
- return 0;
-
- 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(&ctxt, &mmio_ro_emulate_ops);
-
- switch ( rc )
- {
- case X86EMUL_EXCEPTION:
- /*
- * This emulation only covers writes to MMCFG space or read-only MFNs.
- * We tolerate #PF (from hitting an adjacent page or a successful
- * concurrent pagetable update). Anything else is an emulation bug,
- * or a guest playing with the instruction stream under Xen's feet.
- */
- if ( ctxt.event.type == X86_EVENTTYPE_HW_EXCEPTION &&
- ctxt.event.vector == TRAP_page_fault )
- pv_inject_event(&ctxt.event);
- else
- gdprintk(XENLOG_WARNING,
- "Unexpected event (type %u, vector %#x) from emulation\n",
- ctxt.event.type, ctxt.event.vector);
-
- /* Fallthrough */
- case X86EMUL_OKAY:
-
- if ( ctxt.retire.singlestep )
- pv_inject_hw_exception(TRAP_debug, X86_EVENT_NO_EC);
-
- /* Fallthrough */
- case X86EMUL_RETRY:
- perfc_incr(ptwr_emulations);
- return EXCRET_fault_fixed;
- }
-
- return 0;
-}
-
void *alloc_xen_pagetable(void)
{
if ( system_state != SYS_STATE_early_boot )
diff --git a/xen/arch/x86/pv/Makefile b/xen/arch/x86/pv/Makefile
index cbd890c5f2..016b1b6e8f 100644
--- a/xen/arch/x86/pv/Makefile
+++ b/xen/arch/x86/pv/Makefile
@@ -3,6 +3,7 @@ obj-y += domain.o
obj-y += emulate.o
obj-y += emul-gate-op.o
obj-y += emul-inv-op.o
+obj-y += emul-mmio-op.o
obj-y += emul-priv-op.o
obj-y += emul-ptwr-op.o
obj-y += hypercall.o
diff --git a/xen/arch/x86/pv/emul-mmio-op.c b/xen/arch/x86/pv/emul-mmio-op.c
new file mode 100644
index 0000000000..ee5c684777
--- /dev/null
+++ b/xen/arch/x86/pv/emul-mmio-op.c
@@ -0,0 +1,166 @@
+/******************************************************************************
+ * arch/x86/emul-mmio-op.c
+ *
+ * Readonly MMIO emulation for PV guests
+ *
+ * Copyright (c) 2002-2005 K A Fraser
+ * Copyright (c) 2004 Christian Limpach
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <xen/rangeset.h>
+#include <xen/sched.h>
+
+#include <asm/domain.h>
+#include <asm/mm.h>
+#include <asm/pci.h>
+#include <asm/pv/mm.h>
+
+#include "emulate.h"
+
+/*************************
+ * fault handling for read-only MMIO pages
+ */
+
+static const struct x86_emulate_ops mmio_ro_emulate_ops = {
+ .read = x86emul_unhandleable_rw,
+ .insn_fetch = pv_emul_ptwr_read,
+ .write = mmio_ro_emulated_write,
+ .validate = pv_emul_is_mem_write,
+ .cpuid = pv_emul_cpuid,
+};
+
+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 = ctxt->data;
+
+ /*
+ * Only allow naturally-aligned stores no wider than 4 bytes to the
+ * original %cr2 address.
+ */
+ if ( ((bytes | offset) & (bytes - 1)) || bytes > 4 || !bytes ||
+ offset != mmio_ctxt->cr2 )
+ {
+ gdprintk(XENLOG_WARNING, "bad write (cr2=%lx, addr=%lx, bytes=%u)\n",
+ mmio_ctxt->cr2, offset, bytes);
+ return X86EMUL_UNHANDLEABLE;
+ }
+
+ offset &= 0xfff;
+ if ( pci_conf_write_intercept(mmio_ctxt->seg, mmio_ctxt->bdf,
+ offset, bytes, p_data) >= 0 )
+ pci_mmcfg_write(mmio_ctxt->seg, PCI_BUS(mmio_ctxt->bdf),
+ PCI_DEVFN2(mmio_ctxt->bdf), offset, bytes,
+ *(uint32_t *)p_data);
+
+ return X86EMUL_OKAY;
+}
+
+static const struct x86_emulate_ops mmcfg_intercept_ops = {
+ .read = x86emul_unhandleable_rw,
+ .insn_fetch = pv_emul_ptwr_read,
+ .write = mmcfg_intercept_write,
+ .validate = pv_emul_is_mem_write,
+ .cpuid = pv_emul_cpuid,
+};
+
+/* Check if guest is trying to modify a r/o MMIO page. */
+int mmio_ro_do_page_fault(struct vcpu *v, unsigned long addr,
+ struct cpu_user_regs *regs)
+{
+ 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 = { .cr2 = addr };
+ struct x86_emulate_ctxt ctxt = {
+ .regs = regs,
+ .vendor = v->domain->arch.cpuid->x86_vendor,
+ .addr_size = addr_size,
+ .sp_size = addr_size,
+ .lma = !is_pv_32bit_vcpu(v),
+ .data = &mmio_ro_ctxt,
+ };
+ int rc;
+
+ /* Attempt to read the PTE that maps the VA being accessed. */
+ pv_get_guest_eff_l1e(addr, &pte);
+
+ /* We are looking only for read-only mappings of MMIO pages. */
+ if ( ((l1e_get_flags(pte) & (_PAGE_PRESENT|_PAGE_RW)) != _PAGE_PRESENT) )
+ return 0;
+
+ mfn = l1e_get_pfn(pte);
+ if ( mfn_valid(_mfn(mfn)) )
+ {
+ struct page_info *page = mfn_to_page(mfn);
+ struct domain *owner = page_get_owner_and_reference(page);
+
+ if ( owner )
+ put_page(page);
+ if ( owner != dom_io )
+ return 0;
+ }
+
+ if ( !rangeset_contains_singleton(mmio_ro_ranges, mfn) )
+ return 0;
+
+ 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(&ctxt, &mmio_ro_emulate_ops);
+
+ switch ( rc )
+ {
+ case X86EMUL_EXCEPTION:
+ /*
+ * This emulation only covers writes to MMCFG space or read-only MFNs.
+ * We tolerate #PF (from hitting an adjacent page or a successful
+ * concurrent pagetable update). Anything else is an emulation bug,
+ * or a guest playing with the instruction stream under Xen's feet.
+ */
+ if ( ctxt.event.type == X86_EVENTTYPE_HW_EXCEPTION &&
+ ctxt.event.vector == TRAP_page_fault )
+ pv_inject_event(&ctxt.event);
+ else
+ gdprintk(XENLOG_WARNING,
+ "Unexpected event (type %u, vector %#x) from emulation\n",
+ ctxt.event.type, ctxt.event.vector);
+
+ /* Fallthrough */
+ case X86EMUL_OKAY:
+
+ if ( ctxt.retire.singlestep )
+ pv_inject_hw_exception(TRAP_debug, X86_EVENT_NO_EC);
+
+ /* Fallthrough */
+ case X86EMUL_RETRY:
+ perfc_incr(ptwr_emulations);
+ return EXCRET_fault_fixed;
+ }
+
+ return 0;
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
--
2.11.0
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