From: Wei Liu <wei.liu2@citrix.com>
To: Xen-devel <xen-devel@lists.xenproject.org>
Cc: George Dunlap <george.dunlap@eu.citrix.com>,
Andrew Cooper <andrew.cooper3@citrix.com>,
Wei Liu <wei.liu2@citrix.com>, Jan Beulich <JBeulich@suse.com>
Subject: [PATCH v3 12/21] x86/mm: split out readonly MMIO emulation code
Date: Thu, 20 Jul 2017 17:04:17 +0100 [thread overview]
Message-ID: <20170720160426.2343-13-wei.liu2@citrix.com> (raw)
In-Reply-To: <20170720160426.2343-1-wei.liu2@citrix.com>
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@citrix.com>
---
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
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel
next prev parent reply other threads:[~2017-07-20 16:16 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-20 16:04 [PATCH v3 00/21] x86: refactor mm.c (the easy part) Wei Liu
2017-07-20 16:04 ` [PATCH v3 01/21] x86/mm: carve out create_grant_pv_mapping Wei Liu
2017-08-28 15:16 ` George Dunlap
2017-07-20 16:04 ` [PATCH v3 02/21] x86/mm: carve out replace_grant_pv_mapping Wei Liu
2017-08-28 15:19 ` George Dunlap
2017-07-20 16:04 ` [PATCH v3 03/21] x86/mm: split HVM grant table code to hvm/grant_table.c Wei Liu
2017-07-20 16:04 ` [PATCH v3 04/21] x86/mm: lift PAGE_CACHE_ATTRS to page.h Wei Liu
2017-07-20 16:04 ` [PATCH v3 05/21] x86/mm: document the return values from get_page_from_l*e Wei Liu
2017-07-20 16:04 ` [PATCH v3 06/21] x86: move pv_emul_is_mem_write to pv/emulate.c Wei Liu
2017-07-20 16:04 ` [PATCH v3 07/21] x86/mm: move and rename guest_get_eff{, kern}_l1e Wei Liu
2017-07-20 16:04 ` [PATCH v3 08/21] x86/mm: export get_page_from_pagenr Wei Liu
2017-07-20 16:04 ` [PATCH v3 09/21] x86/mm: rename and move update_intpte Wei Liu
2017-07-20 16:04 ` [PATCH v3 10/21] x86/mm: move {un, }adjust_guest_* to pv/mm.h Wei Liu
2017-07-20 16:04 ` [PATCH v3 11/21] x86/mm: split out writable pagetable emulation code Wei Liu
2017-07-20 16:04 ` Wei Liu [this message]
2017-07-20 16:04 ` [PATCH v3 13/21] x86/mm: remove the unused inclusion of pv/emulate.h Wei Liu
2017-07-20 16:04 ` [PATCH v3 14/21] x86/mm: move and rename guest_{, un}map_l1e Wei Liu
2017-07-20 16:04 ` [PATCH v3 15/21] x86/mm: split out PV grant table code Wei Liu
2017-07-20 16:04 ` [PATCH v3 16/21] x86/mm: split out descriptor " Wei Liu
2017-07-20 16:04 ` [PATCH v3 17/21] x86/mm: move compat descriptor handling code Wei Liu
2017-07-20 16:04 ` [PATCH v3 18/21] x86/mm: move and rename map_ldt_shadow_page Wei Liu
2017-07-20 16:04 ` [PATCH v3 19/21] x86/mm: factor out pv_arch_init_memory Wei Liu
2017-07-20 16:04 ` [PATCH v3 20/21] x86/mm: move l4 table setup code Wei Liu
2017-07-20 16:04 ` [PATCH v3 21/21] x86/mm: add "pv_" prefix to new_guest_cr3 Wei Liu
2017-07-30 6:26 ` [PATCH v3 00/21] x86: refactor mm.c (the easy part) Jan Beulich
2017-07-30 9:23 ` Wei Liu
2017-07-30 15:43 ` [PATCH v3 extra 00/11] x86: refactor mm.c: page APIs and hypercalls Wei Liu
2017-07-30 15:43 ` [PATCH v3 extra 01/11] x86: add pv_ prefix to {alloc, free}_page_type Wei Liu
2017-07-30 15:43 ` [PATCH v3 extra 02/11] x86/mm: export more get/put page functions Wei Liu
2017-07-30 15:43 ` [PATCH v3 extra 03/11] x86/mm: move and add pv_ prefix to create_pae_xen_mappings Wei Liu
2017-07-30 15:43 ` [PATCH v3 extra 04/11] x86/mm: move disallow_mask variable and macros Wei Liu
2017-07-30 15:43 ` [PATCH v3 extra 05/11] x86/mm: move pv_{alloc, free}_page_type Wei Liu
2017-07-30 15:43 ` [PATCH v3 extra 06/11] x86/mm: move and add pv_ prefix to invalidate_shadow_ldt Wei Liu
2017-07-30 15:43 ` [PATCH v3 extra 07/11] x86/mm: move PV hypercalls to pv/mm-hypercalls.c Wei Liu
2017-07-30 15:43 ` [PATCH v3 extra 08/11] x86/mm: remove the now unused inclusion of pv/mm.h Wei Liu
2017-07-30 15:43 ` [PATCH v3 extra 09/11] x86/mm: use put_page_type_preemptible in put_page_from_l{2, 3}e Wei Liu
2017-07-30 15:43 ` [PATCH v3 extra 10/11] x86/mm: move {get, put}_page_from_l{2, 3, 4}e Wei Liu
2017-07-30 15:43 ` [PATCH v3 extra 11/11] x86/mm: move description of x86 page table API to pv/mm.c Wei Liu
2017-07-31 9:58 ` [PATCH v3 extra 00/11] x86: refactor mm.c: page APIs and hypercalls Jan Beulich
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20170720160426.2343-13-wei.liu2@citrix.com \
--to=wei.liu2@citrix.com \
--cc=JBeulich@suse.com \
--cc=andrew.cooper3@citrix.com \
--cc=george.dunlap@eu.citrix.com \
--cc=xen-devel@lists.xenproject.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).