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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v4 04/27] x86: move PV invalid op emulation code
On Wed, Jun 21, 2017 at 12:15:46AM -0600, Jan Beulich wrote:
> >>> On 20.06.17 at 18:25, <wei.liu2@xxxxxxxxxx> wrote:
> > On Tue, Jun 20, 2017 at 10:21:27AM -0600, Jan Beulich wrote:
> >> >>> On 08.06.17 at 19:11, <wei.liu2@xxxxxxxxxx> wrote:
> >> > @@ -1053,8 +982,8 @@ void do_invalid_op(struct cpu_user_regs *regs)
> >> >
> >> > if ( likely(guest_mode(regs)) )
> >> > {
> >> > - if ( !emulate_invalid_rdtscp(regs) &&
> >> > - !emulate_forced_invalid_op(regs) )
> >> > + if ( !pv_emulate_invalid_rdtscp(regs) &&
> >> > + !pv_emulate_forced_invalid_op(regs) )
> >>
> >> I wonder if the first couldn't be called by the second, making it
> >> unnecessary to export both. Or maybe have a wrapper
> >> pv_emulate_invalid_op() around both.
> >>
> >
> > Do you want me to refactor and move code in the same patch? Wouldn't
> > that make it hard for you to review?
>
> Why - especially in the wrapper variant you'd move both functions
> unchanged (perhaps even with the names left as they are), and
> merely add the wrapper (and of course use it in the code fragment
> above). That'll make review rather simple, as you'll still be able to
> state that you left both existing functions unchanged.
OK
---8<---
From 50dfe1fe116c28a3953f0b72acc7b1dee4136e2b Mon Sep 17 00:00:00 2001
From: Wei Liu <wei.liu2@xxxxxxxxxx>
Date: Mon, 5 Jun 2017 13:07:16 +0100
Subject: [PATCH] x86: move PV invalid op emulation code
Move the code to pv/emul-inv-op.c. Both functions are unchanged.
Provide pv_emulate_invalid_op and use it in traps.c.
Signed-off-by: Wei Liu <wei.liu2@xxxxxxxxxx>
---
xen/arch/x86/pv/Makefile | 1 +
xen/arch/x86/pv/emul-inv-op.c | 128 +++++++++++++++++++++++++++++++++++++++++
xen/arch/x86/traps.c | 74 +-----------------------
xen/include/asm-x86/pv/traps.h | 2 +
4 files changed, 132 insertions(+), 73 deletions(-)
create mode 100644 xen/arch/x86/pv/emul-inv-op.c
diff --git a/xen/arch/x86/pv/Makefile b/xen/arch/x86/pv/Makefile
index 1f6fbd3f5c..42ca64dc9e 100644
--- a/xen/arch/x86/pv/Makefile
+++ b/xen/arch/x86/pv/Makefile
@@ -5,5 +5,6 @@ obj-bin-y += dom0_build.init.o
obj-y += domain.o
obj-y += emulate.o
obj-y += emul-gate-op.o
+obj-y += emul-inv-op.o
obj-y += emul-priv-op.o
obj-bin-y += gpr_switch.o
diff --git a/xen/arch/x86/pv/emul-inv-op.c b/xen/arch/x86/pv/emul-inv-op.c
new file mode 100644
index 0000000000..a1c56da171
--- /dev/null
+++ b/xen/arch/x86/pv/emul-inv-op.c
@@ -0,0 +1,128 @@
+/******************************************************************************
+ * arch/x86/pv/emul-inv-op.c
+ *
+ * Emulate invalid op for PV guests
+ *
+ * Modifications to Linux original are copyright (c) 2002-2004, K A Fraser
+ *
+ * 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/errno.h>
+#include <xen/event.h>
+#include <xen/guest_access.h>
+#include <xen/iocap.h>
+#include <xen/spinlock.h>
+#include <xen/trace.h>
+
+#include <asm/apic.h>
+#include <asm/debugreg.h>
+#include <asm/hpet.h>
+#include <asm/hypercall.h>
+#include <asm/mc146818rtc.h>
+#include <asm/p2m.h>
+#include <asm/pv/traps.h>
+#include <asm/shared.h>
+#include <asm/traps.h>
+#include <asm/x86_emulate.h>
+
+#include <xsm/xsm.h>
+
+#include "emulate.h"
+
+static int emulate_invalid_rdtscp(struct cpu_user_regs *regs)
+{
+ char opcode[3];
+ unsigned long eip, rc;
+ struct vcpu *v = current;
+
+ eip = regs->rip;
+ if ( (rc = copy_from_user(opcode, (char *)eip, sizeof(opcode))) != 0 )
+ {
+ pv_inject_page_fault(0, eip + sizeof(opcode) - rc);
+ return EXCRET_fault_fixed;
+ }
+ if ( memcmp(opcode, "\xf\x1\xf9", sizeof(opcode)) )
+ return 0;
+ eip += sizeof(opcode);
+ pv_soft_rdtsc(v, regs, 1);
+ pv_emul_instruction_done(regs, eip);
+ return EXCRET_fault_fixed;
+}
+
+static int emulate_forced_invalid_op(struct cpu_user_regs *regs)
+{
+ char sig[5], instr[2];
+ unsigned long eip, rc;
+ struct cpuid_leaf res;
+
+ eip = regs->rip;
+
+ /* Check for forced emulation signature: ud2 ; .ascii "xen". */
+ if ( (rc = copy_from_user(sig, (char *)eip, sizeof(sig))) != 0 )
+ {
+ pv_inject_page_fault(0, eip + sizeof(sig) - rc);
+ return EXCRET_fault_fixed;
+ }
+ if ( memcmp(sig, "\xf\xbxen", sizeof(sig)) )
+ return 0;
+ eip += sizeof(sig);
+
+ /* We only emulate CPUID. */
+ if ( ( rc = copy_from_user(instr, (char *)eip, sizeof(instr))) != 0 )
+ {
+ pv_inject_page_fault(0, eip + sizeof(instr) - rc);
+ return EXCRET_fault_fixed;
+ }
+ if ( memcmp(instr, "\xf\xa2", sizeof(instr)) )
+ return 0;
+
+ /* If cpuid faulting is enabled and CPL>0 inject a #GP in place of #UD. */
+ if ( current->arch.cpuid_faulting && !guest_kernel_mode(current, regs) )
+ {
+ regs->rip = eip;
+ pv_inject_hw_exception(TRAP_gp_fault, regs->error_code);
+ return EXCRET_fault_fixed;
+ }
+
+ eip += sizeof(instr);
+
+ guest_cpuid(current, regs->eax, regs->ecx, &res);
+
+ regs->rax = res.a;
+ regs->rbx = res.b;
+ regs->rcx = res.c;
+ regs->rdx = res.d;
+
+ pv_emul_instruction_done(regs, eip);
+
+ trace_trap_one_addr(TRC_PV_FORCED_INVALID_OP, regs->rip);
+
+ return EXCRET_fault_fixed;
+}
+
+int pv_emulate_invalid_op(struct cpu_user_regs *regs)
+{
+ return !emulate_invalid_rdtscp(regs) && !emulate_forced_invalid_op(regs);
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index 7b781f17db..88dfd464e7 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -968,77 +968,6 @@ void cpuid_hypervisor_leaves(const struct vcpu *v,
uint32_t leaf,
}
}
-static int emulate_invalid_rdtscp(struct cpu_user_regs *regs)
-{
- char opcode[3];
- unsigned long eip, rc;
- struct vcpu *v = current;
-
- eip = regs->rip;
- if ( (rc = copy_from_user(opcode, (char *)eip, sizeof(opcode))) != 0 )
- {
- pv_inject_page_fault(0, eip + sizeof(opcode) - rc);
- return EXCRET_fault_fixed;
- }
- if ( memcmp(opcode, "\xf\x1\xf9", sizeof(opcode)) )
- return 0;
- eip += sizeof(opcode);
- pv_soft_rdtsc(v, regs, 1);
- pv_emul_instruction_done(regs, eip);
- return EXCRET_fault_fixed;
-}
-
-static int emulate_forced_invalid_op(struct cpu_user_regs *regs)
-{
- char sig[5], instr[2];
- unsigned long eip, rc;
- struct cpuid_leaf res;
-
- eip = regs->rip;
-
- /* Check for forced emulation signature: ud2 ; .ascii "xen". */
- if ( (rc = copy_from_user(sig, (char *)eip, sizeof(sig))) != 0 )
- {
- pv_inject_page_fault(0, eip + sizeof(sig) - rc);
- return EXCRET_fault_fixed;
- }
- if ( memcmp(sig, "\xf\xbxen", sizeof(sig)) )
- return 0;
- eip += sizeof(sig);
-
- /* We only emulate CPUID. */
- if ( ( rc = copy_from_user(instr, (char *)eip, sizeof(instr))) != 0 )
- {
- pv_inject_page_fault(0, eip + sizeof(instr) - rc);
- return EXCRET_fault_fixed;
- }
- if ( memcmp(instr, "\xf\xa2", sizeof(instr)) )
- return 0;
-
- /* If cpuid faulting is enabled and CPL>0 inject a #GP in place of #UD. */
- if ( current->arch.cpuid_faulting && !guest_kernel_mode(current, regs) )
- {
- regs->rip = eip;
- pv_inject_hw_exception(TRAP_gp_fault, regs->error_code);
- return EXCRET_fault_fixed;
- }
-
- eip += sizeof(instr);
-
- guest_cpuid(current, regs->eax, regs->ecx, &res);
-
- regs->rax = res.a;
- regs->rbx = res.b;
- regs->rcx = res.c;
- regs->rdx = res.d;
-
- pv_emul_instruction_done(regs, eip);
-
- trace_trap_one_addr(TRC_PV_FORCED_INVALID_OP, regs->rip);
-
- return EXCRET_fault_fixed;
-}
-
void do_invalid_op(struct cpu_user_regs *regs)
{
const struct bug_frame *bug = NULL;
@@ -1053,8 +982,7 @@ void do_invalid_op(struct cpu_user_regs *regs)
if ( likely(guest_mode(regs)) )
{
- if ( !emulate_invalid_rdtscp(regs) &&
- !emulate_forced_invalid_op(regs) )
+ if ( pv_emulate_invalid_op(regs) )
pv_inject_hw_exception(TRAP_invalid_op, X86_EVENT_NO_EC);
return;
}
diff --git a/xen/include/asm-x86/pv/traps.h b/xen/include/asm-x86/pv/traps.h
index b1b6b1d0ad..458028a94b 100644
--- a/xen/include/asm-x86/pv/traps.h
+++ b/xen/include/asm-x86/pv/traps.h
@@ -27,11 +27,13 @@
int pv_emulate_privileged_op(struct cpu_user_regs *regs);
void pv_emulate_gate_op(struct cpu_user_regs *regs);
+int pv_emulate_invalid_op(struct cpu_user_regs *regs);
#else /* !CONFIG_PV */
static inline int pv_emulate_privileged_op(struct cpu_user_regs *regs) {
return 0; }
static inline void pv_emulate_gate_op(struct cpu_user_regs *regs) {}
+static int pv_emulate_invalid_op(struct cpu_user_regs *regs) { return 0; }
#endif /* CONFIG_PV */
--
2.11.0
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