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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen-unstable] [HVM] Cache segment-register contents during PTE-update emulations.
# HG changeset patch
# User kfraser@xxxxxxxxxxxxxxxxxxxxx
# Node ID 5c82a274733e1cc9effda2fb0154d2bb40501808
# Parent 1e6f9222a1e11e49502d837eb349d0773078a156
[HVM] Cache segment-register contents during PTE-update emulations.
Also clean up page-fault propagation to inject the correct error
code and CR2 value.
Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>
---
xen/arch/x86/hvm/svm/svm.c | 10 +++--
xen/arch/x86/hvm/vmx/vmx.c | 10 +++--
xen/arch/x86/mm/shadow/common.c | 71 ++++++++++++++++++++++++-------------
xen/arch/x86/mm/shadow/multi.c | 74 ++++++++++++++++++++-------------------
xen/arch/x86/mm/shadow/private.h | 13 ++++++
xen/include/asm-x86/domain.h | 2 -
xen/include/asm-x86/hvm/hvm.h | 9 ++--
xen/include/asm-x86/shadow.h | 8 ++--
8 files changed, 120 insertions(+), 77 deletions(-)
diff -r 1e6f9222a1e1 -r 5c82a274733e xen/arch/x86/hvm/svm/svm.c
--- a/xen/arch/x86/hvm/svm/svm.c Fri Dec 01 15:12:48 2006 +0000
+++ b/xen/arch/x86/hvm/svm/svm.c Fri Dec 01 15:45:59 2006 +0000
@@ -812,9 +812,13 @@ static void svm_vcpu_destroy(struct vcpu
svm_destroy_vmcb(v);
}
-static void svm_hvm_inject_exception(unsigned int trapnr, int errcode)
-{
- svm_inject_exception(current, trapnr, (errcode != -1), errcode);
+static void svm_hvm_inject_exception(
+ unsigned int trapnr, int errcode, unsigned long cr2)
+{
+ struct vcpu *v = current;
+ svm_inject_exception(v, trapnr, (errcode != -1), errcode);
+ if ( trapnr == TRAP_page_fault )
+ v->arch.hvm_svm.vmcb->cr2 = v->arch.hvm_svm.cpu_cr2 = cr2;
}
int start_svm(void)
diff -r 1e6f9222a1e1 -r 5c82a274733e xen/arch/x86/hvm/vmx/vmx.c
--- a/xen/arch/x86/hvm/vmx/vmx.c Fri Dec 01 15:12:48 2006 +0000
+++ b/xen/arch/x86/hvm/vmx/vmx.c Fri Dec 01 15:45:59 2006 +0000
@@ -715,9 +715,13 @@ static void vmx_update_host_cr3(struct v
__vmwrite(HOST_CR3, v->arch.cr3);
}
-static void vmx_inject_exception(unsigned int trapnr, int errcode)
-{
- vmx_inject_hw_exception(current, trapnr, errcode);
+static void vmx_inject_exception(
+ unsigned int trapnr, int errcode, unsigned long cr2)
+{
+ struct vcpu *v = current;
+ vmx_inject_hw_exception(v, trapnr, errcode);
+ if ( trapnr == TRAP_page_fault )
+ v->arch.hvm_vmx.cpu_cr2 = cr2;
}
/* Setup HVM interfaces */
diff -r 1e6f9222a1e1 -r 5c82a274733e xen/arch/x86/mm/shadow/common.c
--- a/xen/arch/x86/mm/shadow/common.c Fri Dec 01 15:12:48 2006 +0000
+++ b/xen/arch/x86/mm/shadow/common.c Fri Dec 01 15:45:59 2006 +0000
@@ -69,42 +69,52 @@ int _shadow_mode_refcounts(struct domain
/* x86 emulator support for the shadow code
*/
+struct segment_register *hvm_get_seg_reg(
+ enum x86_segment seg, struct sh_emulate_ctxt *sh_ctxt)
+{
+ struct segment_register *seg_reg = &sh_ctxt->seg_reg[seg];
+ if ( !__test_and_set_bit(seg, &sh_ctxt->valid_seg_regs) )
+ hvm_get_segment_register(current, seg, seg_reg);
+ return seg_reg;
+}
+
static int hvm_translate_linear_addr(
enum x86_segment seg,
unsigned long offset,
unsigned int bytes,
unsigned int is_write,
+ struct sh_emulate_ctxt *sh_ctxt,
unsigned long *paddr)
{
- struct segment_register creg, dreg;
+ struct segment_register *creg, *dreg;
unsigned long limit, addr = offset;
uint32_t last_byte;
- hvm_get_segment_register(current, x86_seg_cs, &creg);
- hvm_get_segment_register(current, seg, &dreg);
-
- if ( !creg.attr.fields.l || !hvm_long_mode_enabled(current) )
+ creg = hvm_get_seg_reg(x86_seg_cs, sh_ctxt);
+ dreg = hvm_get_seg_reg(seg, sh_ctxt);
+
+ if ( !creg->attr.fields.l || !hvm_long_mode_enabled(current) )
{
/*
* COMPATIBILITY MODE: Apply segment checks and add base.
*/
/* If this is a store, is the segment a writable data segment? */
- if ( is_write && ((dreg.attr.fields.type & 0xa) != 0x2) )
+ if ( is_write && ((dreg->attr.fields.type & 0xa) != 0x2) )
goto gpf;
/* Calculate the segment limit, including granularity flag. */
- limit = dreg.limit;
- if ( dreg.attr.fields.g )
+ limit = dreg->limit;
+ if ( dreg->attr.fields.g )
limit = (limit << 12) | 0xfff;
last_byte = offset + bytes - 1;
/* Is this a grows-down data segment? Special limit check if so. */
- if ( (dreg.attr.fields.type & 0xc) == 0x4 )
+ if ( (dreg->attr.fields.type & 0xc) == 0x4 )
{
/* Is upper limit 0xFFFF or 0xFFFFFFFF? */
- if ( !dreg.attr.fields.db )
+ if ( !dreg->attr.fields.db )
last_byte = (uint16_t)last_byte;
/* Check first byte and last byte against respective bounds. */
@@ -118,7 +128,7 @@ static int hvm_translate_linear_addr(
* Hardware truncates to 32 bits in compatibility mode.
* It does not truncate to 16 bits in 16-bit address-size mode.
*/
- addr = (uint32_t)(addr + dreg.base);
+ addr = (uint32_t)(addr + dreg->base);
}
else
{
@@ -127,7 +137,7 @@ static int hvm_translate_linear_addr(
*/
if ( (seg == x86_seg_fs) || (seg == x86_seg_gs) )
- addr += dreg.base;
+ addr += dreg->base;
if ( !is_canonical_address(addr) )
goto gpf;
@@ -138,7 +148,7 @@ static int hvm_translate_linear_addr(
gpf:
/* Inject #GP(0). */
- hvm_inject_exception(TRAP_gp_fault, 0);
+ hvm_inject_exception(TRAP_gp_fault, 0, 0);
return X86EMUL_PROPAGATE_FAULT;
}
@@ -149,10 +159,12 @@ sh_x86_emulate_read(enum x86_segment seg
unsigned int bytes,
struct x86_emulate_ctxt *ctxt)
{
+ struct sh_emulate_ctxt *sh_ctxt =
+ container_of(ctxt, struct sh_emulate_ctxt, ctxt);
unsigned long addr;
- int rc;
-
- rc = hvm_translate_linear_addr(seg, offset, bytes, 0, &addr);
+ int rc, errcode;
+
+ rc = hvm_translate_linear_addr(seg, offset, bytes, 0, sh_ctxt, &addr);
if ( rc )
return rc;
@@ -161,7 +173,7 @@ sh_x86_emulate_read(enum x86_segment seg
// It entirely ignores the permissions in the page tables.
// In this case, that is only a user vs supervisor access check.
//
- if ( hvm_copy_from_guest_virt(val, addr, bytes) == 0 )
+ if ( (rc = hvm_copy_from_guest_virt(val, addr, bytes)) == 0 )
{
#if 0
struct vcpu *v = current;
@@ -176,6 +188,8 @@ sh_x86_emulate_read(enum x86_segment seg
* was mapped here. This should never happen: we're here because
* of a write fault at the end of the instruction we're emulating. */
SHADOW_PRINTK("read failed to va %#lx\n", addr);
+ errcode = ring_3(sh_ctxt->ctxt.regs) ? PFEC_user_mode : 0;
+ hvm_inject_exception(TRAP_page_fault, errcode, addr + bytes - rc);
return X86EMUL_PROPAGATE_FAULT;
}
@@ -186,11 +200,13 @@ sh_x86_emulate_write(enum x86_segment se
unsigned int bytes,
struct x86_emulate_ctxt *ctxt)
{
+ struct sh_emulate_ctxt *sh_ctxt =
+ container_of(ctxt, struct sh_emulate_ctxt, ctxt);
struct vcpu *v = current;
unsigned long addr;
int rc;
- rc = hvm_translate_linear_addr(seg, offset, bytes, 1, &addr);
+ rc = hvm_translate_linear_addr(seg, offset, bytes, 1, sh_ctxt, &addr);
if ( rc )
return rc;
@@ -198,7 +214,8 @@ sh_x86_emulate_write(enum x86_segment se
SHADOW_PRINTK("d=%u v=%u a=%#lx v=%#lx bytes=%u\n",
v->domain->domain_id, v->vcpu_id, addr, val, bytes);
#endif
- return v->arch.shadow.mode->x86_emulate_write(v, addr, &val, bytes, ctxt);
+ return v->arch.shadow.mode->x86_emulate_write(
+ v, addr, &val, bytes, sh_ctxt);
}
static int
@@ -209,11 +226,13 @@ sh_x86_emulate_cmpxchg(enum x86_segment
unsigned int bytes,
struct x86_emulate_ctxt *ctxt)
{
+ struct sh_emulate_ctxt *sh_ctxt =
+ container_of(ctxt, struct sh_emulate_ctxt, ctxt);
struct vcpu *v = current;
unsigned long addr;
int rc;
- rc = hvm_translate_linear_addr(seg, offset, bytes, 1, &addr);
+ rc = hvm_translate_linear_addr(seg, offset, bytes, 1, sh_ctxt, &addr);
if ( rc )
return rc;
@@ -221,8 +240,8 @@ sh_x86_emulate_cmpxchg(enum x86_segment
SHADOW_PRINTK("d=%u v=%u a=%#lx o?=%#lx n:=%#lx bytes=%u\n",
v->domain->domain_id, v->vcpu_id, addr, old, new, bytes);
#endif
- return v->arch.shadow.mode->x86_emulate_cmpxchg(v, addr, old, new,
- bytes, ctxt);
+ return v->arch.shadow.mode->x86_emulate_cmpxchg(
+ v, addr, old, new, bytes, sh_ctxt);
}
static int
@@ -234,11 +253,13 @@ sh_x86_emulate_cmpxchg8b(enum x86_segmen
unsigned long new_hi,
struct x86_emulate_ctxt *ctxt)
{
+ struct sh_emulate_ctxt *sh_ctxt =
+ container_of(ctxt, struct sh_emulate_ctxt, ctxt);
struct vcpu *v = current;
unsigned long addr;
int rc;
- rc = hvm_translate_linear_addr(seg, offset, 8, 1, &addr);
+ rc = hvm_translate_linear_addr(seg, offset, 8, 1, sh_ctxt, &addr);
if ( rc )
return rc;
@@ -247,8 +268,8 @@ sh_x86_emulate_cmpxchg8b(enum x86_segmen
v->domain->domain_id, v->vcpu_id, addr, old_hi, old_lo,
new_hi, new_lo, ctxt);
#endif
- return v->arch.shadow.mode->x86_emulate_cmpxchg8b(v, addr, old_lo, old_hi,
- new_lo, new_hi, ctxt);
+ return v->arch.shadow.mode->x86_emulate_cmpxchg8b(
+ v, addr, old_lo, old_hi, new_lo, new_hi, sh_ctxt);
}
diff -r 1e6f9222a1e1 -r 5c82a274733e xen/arch/x86/mm/shadow/multi.c
--- a/xen/arch/x86/mm/shadow/multi.c Fri Dec 01 15:12:48 2006 +0000
+++ b/xen/arch/x86/mm/shadow/multi.c Fri Dec 01 15:45:59 2006 +0000
@@ -2582,7 +2582,7 @@ static int sh_page_fault(struct vcpu *v,
mfn_t gmfn, sl1mfn=_mfn(0);
shadow_l1e_t sl1e, *ptr_sl1e;
paddr_t gpa;
- struct x86_emulate_ctxt emul_ctxt;
+ struct sh_emulate_ctxt emul_ctxt;
int r, mmio;
fetch_type_t ft = 0;
@@ -2808,16 +2808,16 @@ static int sh_page_fault(struct vcpu *v,
return EXCRET_fault_fixed;
emulate:
- /* Take the register set we were called with */
- if ( is_hvm_domain(d) )
- hvm_store_cpu_guest_regs(v, regs, NULL);
- emul_ctxt.regs = regs;
- emul_ctxt.mode = (is_hvm_domain(d) ?
- hvm_guest_x86_mode(v) : X86EMUL_MODE_HOST);
+ if ( !is_hvm_domain(d) )
+ goto not_a_shadow_fault;
+
+ hvm_store_cpu_guest_regs(v, regs, NULL);
+ emul_ctxt.ctxt.regs = regs;
+ emul_ctxt.ctxt.mode = (is_hvm_domain(d) ?
+ hvm_guest_x86_mode(v) : X86EMUL_MODE_HOST);
+ emul_ctxt.valid_seg_regs = 0;
SHADOW_PRINTK("emulate: eip=%#lx\n", regs->eip);
-
- v->arch.shadow.propagate_fault = 0;
/*
* We do not emulate user writes. Instead we use them as a hint that the
@@ -2826,7 +2826,7 @@ static int sh_page_fault(struct vcpu *v,
* We also disallow guest PTE updates from within Xen.
*/
if ( (regs->error_code & PFEC_user_mode) || !guest_mode(regs) ||
- x86_emulate_memop(&emul_ctxt, &shadow_emulator_ops) )
+ x86_emulate_memop(&emul_ctxt.ctxt, &shadow_emulator_ops) )
{
SHADOW_PRINTK("emulator failure, unshadowing mfn %#lx\n",
mfn_x(gmfn));
@@ -2835,19 +2835,10 @@ static int sh_page_fault(struct vcpu *v,
* to support more operations in the emulator. More likely,
* though, this is a hint that this page should not be shadowed. */
shadow_remove_all_shadows(v, gmfn);
- /* This means that actual missing operations will cause the
- * guest to loop on the same page fault. */
- goto done;
- }
-
- /* Emulation triggered another page fault? */
- if ( v->arch.shadow.propagate_fault )
- goto not_a_shadow_fault;
+ }
/* Emulator has changed the user registers: write back */
- if ( is_hvm_domain(d) )
- hvm_load_cpu_guest_regs(v, regs);
-
+ hvm_load_cpu_guest_regs(v, regs);
goto done;
mmio:
@@ -3786,11 +3777,11 @@ int sh_remove_l3_shadow(struct vcpu *v,
* or NULL for error. */
static inline void * emulate_map_dest(struct vcpu *v,
unsigned long vaddr,
- struct x86_emulate_ctxt *ctxt,
+ struct sh_emulate_ctxt *sh_ctxt,
mfn_t *mfnp)
{
walk_t gw;
- u32 flags;
+ u32 flags, errcode;
gfn_t gfn;
mfn_t mfn;
@@ -3801,13 +3792,17 @@ static inline void * emulate_map_dest(st
sh_audit_gw(v, &gw);
unmap_walk(v, &gw);
- if ( !(flags & _PAGE_PRESENT)
- || !(flags & _PAGE_RW)
- || (!(flags & _PAGE_USER) && ring_3(ctxt->regs)) )
- {
- /* This write would have faulted even on bare metal */
- v->arch.shadow.propagate_fault = 1;
- return NULL;
+ if ( !(flags & _PAGE_PRESENT) )
+ {
+ errcode = 0;
+ goto page_fault;
+ }
+
+ if ( !(flags & _PAGE_RW) ||
+ (!(flags & _PAGE_USER) && ring_3(sh_ctxt->ctxt.regs)) )
+ {
+ errcode = PFEC_page_present;
+ goto page_fault;
}
/* Attempted a write to a bad gfn? This should never happen:
@@ -3817,11 +3812,18 @@ static inline void * emulate_map_dest(st
ASSERT(sh_mfn_is_a_page_table(mfn));
*mfnp = mfn;
return sh_map_domain_page(mfn) + (vaddr & ~PAGE_MASK);
+
+ page_fault:
+ errcode |= PFEC_write_access;
+ if ( ring_3(sh_ctxt->ctxt.regs) )
+ errcode |= PFEC_user_mode;
+ hvm_inject_exception(TRAP_page_fault, errcode, vaddr);
+ return NULL;
}
int
sh_x86_emulate_write(struct vcpu *v, unsigned long vaddr, void *src,
- u32 bytes, struct x86_emulate_ctxt *ctxt)
+ u32 bytes, struct sh_emulate_ctxt *sh_ctxt)
{
mfn_t mfn;
void *addr;
@@ -3832,7 +3834,7 @@ sh_x86_emulate_write(struct vcpu *v, uns
ASSERT(shadow_lock_is_acquired(v->domain));
ASSERT(((vaddr & ~PAGE_MASK) + bytes) <= PAGE_SIZE);
- if ( (addr = emulate_map_dest(v, vaddr, ctxt, &mfn)) == NULL )
+ if ( (addr = emulate_map_dest(v, vaddr, sh_ctxt, &mfn)) == NULL )
return X86EMUL_PROPAGATE_FAULT;
memcpy(addr, src, bytes);
@@ -3850,7 +3852,7 @@ int
int
sh_x86_emulate_cmpxchg(struct vcpu *v, unsigned long vaddr,
unsigned long old, unsigned long new,
- unsigned int bytes, struct x86_emulate_ctxt *ctxt)
+ unsigned int bytes, struct sh_emulate_ctxt *sh_ctxt)
{
mfn_t mfn;
void *addr;
@@ -3863,7 +3865,7 @@ sh_x86_emulate_cmpxchg(struct vcpu *v, u
if ( vaddr & (bytes-1) )
return X86EMUL_UNHANDLEABLE;
- if ( (addr = emulate_map_dest(v, vaddr, ctxt, &mfn)) == NULL )
+ if ( (addr = emulate_map_dest(v, vaddr, sh_ctxt, &mfn)) == NULL )
return X86EMUL_PROPAGATE_FAULT;
switch ( bytes )
@@ -3899,7 +3901,7 @@ sh_x86_emulate_cmpxchg8b(struct vcpu *v,
sh_x86_emulate_cmpxchg8b(struct vcpu *v, unsigned long vaddr,
unsigned long old_lo, unsigned long old_hi,
unsigned long new_lo, unsigned long new_hi,
- struct x86_emulate_ctxt *ctxt)
+ struct sh_emulate_ctxt *sh_ctxt)
{
mfn_t mfn;
void *addr;
@@ -3911,7 +3913,7 @@ sh_x86_emulate_cmpxchg8b(struct vcpu *v,
if ( vaddr & 7 )
return X86EMUL_UNHANDLEABLE;
- if ( (addr = emulate_map_dest(v, vaddr, ctxt, &mfn)) == NULL )
+ if ( (addr = emulate_map_dest(v, vaddr, sh_ctxt, &mfn)) == NULL )
return X86EMUL_PROPAGATE_FAULT;
old = (((u64) old_hi) << 32) | (u64) old_lo;
diff -r 1e6f9222a1e1 -r 5c82a274733e xen/arch/x86/mm/shadow/private.h
--- a/xen/arch/x86/mm/shadow/private.h Fri Dec 01 15:12:48 2006 +0000
+++ b/xen/arch/x86/mm/shadow/private.h Fri Dec 01 15:45:59 2006 +0000
@@ -506,6 +506,19 @@ static inline void sh_unpin(struct vcpu
}
}
+
+/**************************************************************************/
+/* PTE-write emulation. */
+
+struct sh_emulate_ctxt {
+ struct x86_emulate_ctxt ctxt;
+
+ /* Cache of segment registers already gathered for this emulation. */
+ unsigned int valid_seg_regs;
+ struct segment_register seg_reg[6];
+};
+
+
#endif /* _XEN_SHADOW_PRIVATE_H */
/*
diff -r 1e6f9222a1e1 -r 5c82a274733e xen/include/asm-x86/domain.h
--- a/xen/include/asm-x86/domain.h Fri Dec 01 15:12:48 2006 +0000
+++ b/xen/include/asm-x86/domain.h Fri Dec 01 15:45:59 2006 +0000
@@ -147,8 +147,6 @@ struct shadow_vcpu {
unsigned long last_writeable_pte_smfn;
/* HVM guest: paging enabled (CR0.PG)? */
unsigned int translate_enabled:1;
- /* Emulated fault needs to be propagated to guest? */
- unsigned int propagate_fault:1;
};
struct arch_vcpu
diff -r 1e6f9222a1e1 -r 5c82a274733e xen/include/asm-x86/hvm/hvm.h
--- a/xen/include/asm-x86/hvm/hvm.h Fri Dec 01 15:12:48 2006 +0000
+++ b/xen/include/asm-x86/hvm/hvm.h Fri Dec 01 15:45:59 2006 +0000
@@ -110,7 +110,8 @@ struct hvm_function_table {
void (*stts)(struct vcpu *v);
void (*set_tsc_offset)(struct vcpu *v, u64 offset);
- void (*inject_exception)(unsigned int trapnr, int errcode);
+ void (*inject_exception)(unsigned int trapnr, int errcode,
+ unsigned long cr2);
void (*init_ap_context)(struct vcpu_guest_context *ctxt,
int vcpuid, int trampoline_vector);
@@ -225,9 +226,9 @@ hvm_init_ap_context(struct vcpu_guest_co
}
static inline void
-hvm_inject_exception(unsigned int trapnr, int errcode)
-{
- hvm_funcs.inject_exception(trapnr, errcode);
+hvm_inject_exception(unsigned int trapnr, int errcode, unsigned long cr2)
+{
+ hvm_funcs.inject_exception(trapnr, errcode, cr2);
}
int hvm_bringup_ap(int vcpuid, int trampoline_vector);
diff -r 1e6f9222a1e1 -r 5c82a274733e xen/include/asm-x86/shadow.h
--- a/xen/include/asm-x86/shadow.h Fri Dec 01 15:12:48 2006 +0000
+++ b/xen/include/asm-x86/shadow.h Fri Dec 01 15:45:59 2006 +0000
@@ -246,7 +246,7 @@ shadow_vcpu_mode_translate(struct vcpu *
/**************************************************************************/
/* Mode-specific entry points into the shadow code */
-struct x86_emulate_ctxt;
+struct sh_emulate_ctxt;
struct shadow_paging_mode {
int (*page_fault )(struct vcpu *v, unsigned long va,
struct cpu_user_regs *regs);
@@ -267,18 +267,18 @@ struct shadow_paging_mode {
void (*detach_old_tables )(struct vcpu *v);
int (*x86_emulate_write )(struct vcpu *v, unsigned long va,
void *src, u32 bytes,
- struct x86_emulate_ctxt *ctxt);
+ struct sh_emulate_ctxt *sh_ctxt);
int (*x86_emulate_cmpxchg )(struct vcpu *v, unsigned long va,
unsigned long old,
unsigned long new,
unsigned int bytes,
- struct x86_emulate_ctxt *ctxt);
+ struct sh_emulate_ctxt *sh_ctxt);
int (*x86_emulate_cmpxchg8b )(struct vcpu *v, unsigned long va,
unsigned long old_lo,
unsigned long old_hi,
unsigned long new_lo,
unsigned long new_hi,
- struct x86_emulate_ctxt *ctxt);
+ struct sh_emulate_ctxt *sh_ctxt);
mfn_t (*make_monitor_table )(struct vcpu *v);
void (*destroy_monitor_table )(struct vcpu *v, mfn_t mmfn);
void * (*guest_map_l1e )(struct vcpu *v, unsigned long va,
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