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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen master] x86/HVM: don't ignore hvm_copy_to_guest_phys() errors during I/O intercept
commit e0c4efbe6dd6822c91b466c34bc6d8aaa935d90f
Author: Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Mon Oct 14 09:52:33 2013 +0200
Commit: Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Mon Oct 14 09:52:33 2013 +0200
x86/HVM: don't ignore hvm_copy_to_guest_phys() errors during I/O intercept
Building upon the extended retry logic we can now also make sure to
not ignore errors resulting from writing data back to guest memory.
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Acked-by: Keir Fraser <keir@xxxxxxx>
---
xen/arch/x86/hvm/intercept.c | 120 +++++++++++++++++++++++++++++++++++++-----
1 files changed, 107 insertions(+), 13 deletions(-)
diff --git a/xen/arch/x86/hvm/intercept.c b/xen/arch/x86/hvm/intercept.c
index 5ac0893..7cc13b5 100644
--- a/xen/arch/x86/hvm/intercept.c
+++ b/xen/arch/x86/hvm/intercept.c
@@ -47,6 +47,7 @@ static int hvm_mmio_access(struct vcpu *v,
hvm_mmio_read_t read_handler,
hvm_mmio_write_t write_handler)
{
+ struct hvm_vcpu_io *vio = &v->arch.hvm_vcpu.hvm_io;
unsigned long data;
int rc = X86EMUL_OKAY, i, step = p->df ? -p->size : p->size;
@@ -54,7 +55,16 @@ static int hvm_mmio_access(struct vcpu *v,
{
if ( p->dir == IOREQ_READ )
{
- rc = read_handler(v, p->addr, p->size, &data);
+ if ( vio->mmio_retrying )
+ {
+ if ( vio->mmio_large_read_bytes != p->size )
+ return X86EMUL_UNHANDLEABLE;
+ memcpy(&data, vio->mmio_large_read, p->size);
+ vio->mmio_large_read_bytes = 0;
+ vio->mmio_retrying = 0;
+ }
+ else
+ rc = read_handler(v, p->addr, p->size, &data);
p->data = data;
}
else /* p->dir == IOREQ_WRITE */
@@ -66,18 +76,48 @@ static int hvm_mmio_access(struct vcpu *v,
{
for ( i = 0; i < p->count; i++ )
{
- int ret;
-
- rc = read_handler(v, p->addr + step * i, p->size, &data);
- if ( rc != X86EMUL_OKAY )
- break;
- ret = hvm_copy_to_guest_phys(p->data + step * i, &data, p->size);
- if ( (ret == HVMCOPY_gfn_paged_out) ||
- (ret == HVMCOPY_gfn_shared) )
+ if ( vio->mmio_retrying )
+ {
+ if ( vio->mmio_large_read_bytes != p->size )
+ return X86EMUL_UNHANDLEABLE;
+ memcpy(&data, vio->mmio_large_read, p->size);
+ vio->mmio_large_read_bytes = 0;
+ vio->mmio_retrying = 0;
+ }
+ else
{
+ rc = read_handler(v, p->addr + step * i, p->size, &data);
+ if ( rc != X86EMUL_OKAY )
+ break;
+ }
+ switch ( hvm_copy_to_guest_phys(p->data + step * i,
+ &data, p->size) )
+ {
+ case HVMCOPY_okay:
+ break;
+ case HVMCOPY_gfn_paged_out:
+ case HVMCOPY_gfn_shared:
rc = X86EMUL_RETRY;
break;
+ case HVMCOPY_bad_gfn_to_mfn:
+ /* Drop the write as real hardware would. */
+ continue;
+ case HVMCOPY_bad_gva_to_gfn:
+ ASSERT(0);
+ /* fall through */
+ default:
+ rc = X86EMUL_UNHANDLEABLE;
+ break;
}
+ if ( rc != X86EMUL_OKAY)
+ break;
+ }
+
+ if ( rc == X86EMUL_RETRY )
+ {
+ vio->mmio_retry = 1;
+ vio->mmio_large_read_bytes = p->size;
+ memcpy(vio->mmio_large_read, &data, p->size);
}
}
else
@@ -109,6 +149,9 @@ static int hvm_mmio_access(struct vcpu *v,
if ( rc != X86EMUL_OKAY )
break;
}
+
+ if ( rc == X86EMUL_RETRY )
+ vio->mmio_retry = 1;
}
if ( i != 0 )
@@ -137,6 +180,7 @@ int hvm_mmio_intercept(ioreq_t *p)
static int process_portio_intercept(portio_action_t action, ioreq_t *p)
{
+ struct hvm_vcpu_io *vio = ¤t->arch.hvm_vcpu.hvm_io;
int rc = X86EMUL_OKAY, i, step = p->df ? -p->size : p->size;
uint32_t data;
@@ -144,7 +188,16 @@ static int process_portio_intercept(portio_action_t
action, ioreq_t *p)
{
if ( p->dir == IOREQ_READ )
{
- rc = action(IOREQ_READ, p->addr, p->size, &data);
+ if ( vio->mmio_retrying )
+ {
+ if ( vio->mmio_large_read_bytes != p->size )
+ return X86EMUL_UNHANDLEABLE;
+ memcpy(&data, vio->mmio_large_read, p->size);
+ vio->mmio_large_read_bytes = 0;
+ vio->mmio_retrying = 0;
+ }
+ else
+ rc = action(IOREQ_READ, p->addr, p->size, &data);
p->data = data;
}
else
@@ -159,10 +212,48 @@ static int process_portio_intercept(portio_action_t
action, ioreq_t *p)
{
for ( i = 0; i < p->count; i++ )
{
- rc = action(IOREQ_READ, p->addr, p->size, &data);
- if ( rc != X86EMUL_OKAY )
+ if ( vio->mmio_retrying )
+ {
+ if ( vio->mmio_large_read_bytes != p->size )
+ return X86EMUL_UNHANDLEABLE;
+ memcpy(&data, vio->mmio_large_read, p->size);
+ vio->mmio_large_read_bytes = 0;
+ vio->mmio_retrying = 0;
+ }
+ else
+ {
+ rc = action(IOREQ_READ, p->addr, p->size, &data);
+ if ( rc != X86EMUL_OKAY )
+ break;
+ }
+ switch ( hvm_copy_to_guest_phys(p->data + step * i,
+ &data, p->size) )
+ {
+ case HVMCOPY_okay:
+ break;
+ case HVMCOPY_gfn_paged_out:
+ case HVMCOPY_gfn_shared:
+ rc = X86EMUL_RETRY;
break;
- (void)hvm_copy_to_guest_phys(p->data + step * i, &data, p->size);
+ case HVMCOPY_bad_gfn_to_mfn:
+ /* Drop the write as real hardware would. */
+ continue;
+ case HVMCOPY_bad_gva_to_gfn:
+ ASSERT(0);
+ /* fall through */
+ default:
+ rc = X86EMUL_UNHANDLEABLE;
+ break;
+ }
+ if ( rc != X86EMUL_OKAY)
+ break;
+ }
+
+ if ( rc == X86EMUL_RETRY )
+ {
+ vio->mmio_retry = 1;
+ vio->mmio_large_read_bytes = p->size;
+ memcpy(vio->mmio_large_read, &data, p->size);
}
}
else /* p->dir == IOREQ_WRITE */
@@ -195,6 +286,9 @@ static int process_portio_intercept(portio_action_t action,
ioreq_t *p)
if ( rc != X86EMUL_OKAY )
break;
}
+
+ if ( rc == X86EMUL_RETRY )
+ vio->mmio_retry = 1;
}
if ( i != 0 )
--
generated by git-patchbot for /home/xen/git/xen.git#master
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