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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen staging] libxc/restore: Introduce functionality to simplify blob handling
commit 59e1f6d897102dd53abd77d84a308a4f308ddf06
Author: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Wed Dec 18 19:01:57 2019 +0000
Commit: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Wed Jan 15 15:22:28 2020 +0000
libxc/restore: Introduce functionality to simplify blob handling
During migration, we buffer several blobs of data which ultimately need
handing back to Xen at an appropriate time.
Currently, this is all handled in an ad-hoc manner, but more blobs are soon
going to be added. Introduce xc_sr_blob to encapsulate a ptr/size pair, and
update_blob() to handle the memory management aspects.
Switch the HVM_CONTEXT and the four PV_VCPU_* blobs over to this new
infrastructure. No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Acked-by: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
---
tools/libxc/xc_sr_common.h | 43 +++++++++++++++++++-----
tools/libxc/xc_sr_restore_x86_hvm.c | 21 ++++--------
tools/libxc/xc_sr_restore_x86_pv.c | 67 ++++++++++++++-----------------------
3 files changed, 66 insertions(+), 65 deletions(-)
diff --git a/tools/libxc/xc_sr_common.h b/tools/libxc/xc_sr_common.h
index a145a15301..9caad8bfcb 100644
--- a/tools/libxc/xc_sr_common.h
+++ b/tools/libxc/xc_sr_common.h
@@ -165,13 +165,38 @@ struct xc_sr_restore_ops
int (*cleanup)(struct xc_sr_context *ctx);
};
-/* x86 PV per-vcpu storage structure for blobs heading Xen-wards. */
-struct xc_sr_x86_pv_restore_vcpu
+/* Wrapper for blobs of data heading Xen-wards. */
+struct xc_sr_blob
{
- void *basic, *extd, *xsave, *msr;
- size_t basicsz, extdsz, xsavesz, msrsz;
+ void *ptr;
+ size_t size;
};
+/*
+ * Update a blob. Duplicate src/size, freeing the old blob if necessary. May
+ * fail due to memory allocation.
+ */
+static inline int update_blob(struct xc_sr_blob *blob,
+ const void *src, size_t size)
+{
+ void *ptr;
+
+ if ( !src || !size )
+ {
+ errno = EINVAL;
+ return -1;
+ }
+
+ if ( (ptr = malloc(size)) == NULL )
+ return -1;
+
+ free(blob->ptr);
+ blob->ptr = memcpy(ptr, src, size);
+ blob->size = size;
+
+ return 0;
+}
+
struct xc_sr_context
{
xc_interface *xch;
@@ -306,8 +331,11 @@ struct xc_sr_context
/* Types for each page (bounded by max_pfn). */
uint32_t *pfn_types;
- /* Vcpu context blobs. */
- struct xc_sr_x86_pv_restore_vcpu *vcpus;
+ /* x86 PV per-vcpu storage structure for blobs. */
+ struct xc_sr_x86_pv_restore_vcpu
+ {
+ struct xc_sr_blob basic, extd, xsave, msr;
+ } *vcpus;
unsigned nr_vcpus;
} restore;
};
@@ -327,8 +355,7 @@ struct xc_sr_context
struct
{
/* HVM context blob. */
- void *context;
- size_t contextsz;
+ struct xc_sr_blob context;
} restore;
};
} x86_hvm;
diff --git a/tools/libxc/xc_sr_restore_x86_hvm.c
b/tools/libxc/xc_sr_restore_x86_hvm.c
index 4a24dc0137..fe7be9bde6 100644
--- a/tools/libxc/xc_sr_restore_x86_hvm.c
+++ b/tools/libxc/xc_sr_restore_x86_hvm.c
@@ -10,21 +10,12 @@ static int handle_hvm_context(struct xc_sr_context *ctx,
struct xc_sr_record *rec)
{
xc_interface *xch = ctx->xch;
- void *p;
+ int rc = update_blob(&ctx->x86_hvm.restore.context, rec->data,
rec->length);
- p = malloc(rec->length);
- if ( !p )
- {
+ if ( rc )
ERROR("Unable to allocate %u bytes for hvm context", rec->length);
- return -1;
- }
- free(ctx->x86_hvm.restore.context);
-
- ctx->x86_hvm.restore.context = memcpy(p, rec->data, rec->length);
- ctx->x86_hvm.restore.contextsz = rec->length;
-
- return 0;
+ return rc;
}
/*
@@ -210,8 +201,8 @@ static int x86_hvm_stream_complete(struct xc_sr_context
*ctx)
}
rc = xc_domain_hvm_setcontext(xch, ctx->domid,
- ctx->x86_hvm.restore.context,
- ctx->x86_hvm.restore.contextsz);
+ ctx->x86_hvm.restore.context.ptr,
+ ctx->x86_hvm.restore.context.size);
if ( rc < 0 )
{
PERROR("Unable to restore HVM context");
@@ -234,7 +225,7 @@ static int x86_hvm_stream_complete(struct xc_sr_context
*ctx)
static int x86_hvm_cleanup(struct xc_sr_context *ctx)
{
- free(ctx->x86_hvm.restore.context);
+ free(ctx->x86_hvm.restore.context.ptr);
return 0;
}
diff --git a/tools/libxc/xc_sr_restore_x86_pv.c
b/tools/libxc/xc_sr_restore_x86_pv.c
index b64f79d4d5..dcc2a7f8c5 100644
--- a/tools/libxc/xc_sr_restore_x86_pv.c
+++ b/tools/libxc/xc_sr_restore_x86_pv.c
@@ -236,7 +236,7 @@ static int process_vcpu_basic(struct xc_sr_context *ctx,
unsigned int vcpuid)
{
xc_interface *xch = ctx->xch;
- vcpu_guest_context_any_t *vcpu = ctx->x86_pv.restore.vcpus[vcpuid].basic;
+ vcpu_guest_context_any_t *vcpu =
ctx->x86_pv.restore.vcpus[vcpuid].basic.ptr;
xen_pfn_t pfn, mfn;
unsigned i, gdt_count;
int rc = -1;
@@ -380,7 +380,7 @@ static int process_vcpu_extended(struct xc_sr_context *ctx,
domctl.cmd = XEN_DOMCTL_set_ext_vcpucontext;
domctl.domain = ctx->domid;
- memcpy(&domctl.u.ext_vcpucontext, vcpu->extd, vcpu->extdsz);
+ memcpy(&domctl.u.ext_vcpucontext, vcpu->extd.ptr, vcpu->extd.size);
if ( xc_domctl(xch, &domctl) != 0 )
{
@@ -404,21 +404,21 @@ static int process_vcpu_xsave(struct xc_sr_context *ctx,
DECLARE_DOMCTL;
DECLARE_HYPERCALL_BUFFER(void, buffer);
- buffer = xc_hypercall_buffer_alloc(xch, buffer, vcpu->xsavesz);
+ buffer = xc_hypercall_buffer_alloc(xch, buffer, vcpu->xsave.size);
if ( !buffer )
{
ERROR("Unable to allocate %zu bytes for xsave hypercall buffer",
- vcpu->xsavesz);
+ vcpu->xsave.size);
return -1;
}
domctl.cmd = XEN_DOMCTL_setvcpuextstate;
domctl.domain = ctx->domid;
domctl.u.vcpuextstate.vcpu = vcpuid;
- domctl.u.vcpuextstate.size = vcpu->xsavesz;
+ domctl.u.vcpuextstate.size = vcpu->xsave.size;
set_xen_guest_handle(domctl.u.vcpuextstate.buffer, buffer);
- memcpy(buffer, vcpu->xsave, vcpu->xsavesz);
+ memcpy(buffer, vcpu->xsave.ptr, vcpu->xsave.size);
rc = xc_domctl(xch, &domctl);
if ( rc )
@@ -442,21 +442,21 @@ static int process_vcpu_msrs(struct xc_sr_context *ctx,
DECLARE_DOMCTL;
DECLARE_HYPERCALL_BUFFER(void, buffer);
- buffer = xc_hypercall_buffer_alloc(xch, buffer, vcpu->msrsz);
+ buffer = xc_hypercall_buffer_alloc(xch, buffer, vcpu->msr.size);
if ( !buffer )
{
ERROR("Unable to allocate %zu bytes for msr hypercall buffer",
- vcpu->msrsz);
+ vcpu->msr.size);
return -1;
}
domctl.cmd = XEN_DOMCTL_set_vcpu_msrs;
domctl.domain = ctx->domid;
domctl.u.vcpu_msrs.vcpu = vcpuid;
- domctl.u.vcpu_msrs.msr_count = vcpu->msrsz / sizeof(xen_domctl_vcpu_msr_t);
+ domctl.u.vcpu_msrs.msr_count = vcpu->msr.size /
sizeof(xen_domctl_vcpu_msr_t);
set_xen_guest_handle(domctl.u.vcpu_msrs.msrs, buffer);
- memcpy(buffer, vcpu->msr, vcpu->msrsz);
+ memcpy(buffer, vcpu->msr.ptr, vcpu->msr.size);
rc = xc_domctl(xch, &domctl);
if ( rc )
@@ -481,7 +481,7 @@ static int update_vcpu_context(struct xc_sr_context *ctx)
{
vcpu = &ctx->x86_pv.restore.vcpus[i];
- if ( vcpu->basic )
+ if ( vcpu->basic.ptr )
{
rc = process_vcpu_basic(ctx, i);
if ( rc )
@@ -493,21 +493,21 @@ static int update_vcpu_context(struct xc_sr_context *ctx)
return -1;
}
- if ( vcpu->extd )
+ if ( vcpu->extd.ptr )
{
rc = process_vcpu_extended(ctx, i);
if ( rc )
return rc;
}
- if ( vcpu->xsave )
+ if ( vcpu->xsave.ptr )
{
rc = process_vcpu_xsave(ctx, i);
if ( rc )
return rc;
}
- if ( vcpu->msr )
+ if ( vcpu->msr.ptr )
{
rc = process_vcpu_msrs(ctx, i);
if ( rc )
@@ -737,7 +737,7 @@ static int handle_x86_pv_vcpu_blob(struct xc_sr_context
*ctx,
struct xc_sr_x86_pv_restore_vcpu *vcpu;
const char *rec_name;
size_t blobsz;
- void *blob;
+ struct xc_sr_blob *blob = NULL;
int rc = -1;
switch ( rec->type )
@@ -811,6 +811,7 @@ static int handle_x86_pv_vcpu_blob(struct xc_sr_context
*ctx,
rec_name, sizeof(*vhdr) + vcpusz, rec->length);
goto out;
}
+ blob = &vcpu->basic;
break;
}
@@ -821,6 +822,7 @@ static int handle_x86_pv_vcpu_blob(struct xc_sr_context
*ctx,
rec_name, sizeof(*vhdr) + 128, rec->length);
goto out;
}
+ blob = &vcpu->extd;
break;
case REC_TYPE_X86_PV_VCPU_XSAVE:
@@ -830,6 +832,7 @@ static int handle_x86_pv_vcpu_blob(struct xc_sr_context
*ctx,
rec_name, sizeof(*vhdr) + 128, rec->length);
goto out;
}
+ blob = &vcpu->xsave;
break;
case REC_TYPE_X86_PV_VCPU_MSRS:
@@ -839,34 +842,14 @@ static int handle_x86_pv_vcpu_blob(struct xc_sr_context
*ctx,
rec_name, blobsz, sizeof(xen_domctl_vcpu_msr_t));
goto out;
}
+ blob = &vcpu->msr;
break;
}
- /* Allocate memory. */
- blob = malloc(blobsz);
- if ( !blob )
- {
+ rc = update_blob(blob, vhdr->context, blobsz);
+ if ( rc )
ERROR("Unable to allocate %zu bytes for vcpu%u %s blob",
blobsz, vhdr->vcpu_id, rec_name);
- goto out;
- }
-
- memcpy(blob, &vhdr->context, blobsz);
-
- /* Stash sideways for later. */
- switch ( rec->type )
- {
-#define RECSTORE(x, y) case REC_TYPE_X86_PV_ ## x: \
- free(y); (y) = blob; (y ## sz) = blobsz; break
-
- RECSTORE(VCPU_BASIC, vcpu->basic);
- RECSTORE(VCPU_EXTENDED, vcpu->extd);
- RECSTORE(VCPU_XSAVE, vcpu->xsave);
- RECSTORE(VCPU_MSRS, vcpu->msr);
-#undef RECSTORE
- }
-
- rc = 0;
out:
return rc;
@@ -1158,10 +1141,10 @@ static int x86_pv_cleanup(struct xc_sr_context *ctx)
struct xc_sr_x86_pv_restore_vcpu *vcpu =
&ctx->x86_pv.restore.vcpus[i];
- free(vcpu->basic);
- free(vcpu->extd);
- free(vcpu->xsave);
- free(vcpu->msr);
+ free(vcpu->basic.ptr);
+ free(vcpu->extd.ptr);
+ free(vcpu->xsave.ptr);
+ free(vcpu->msr.ptr);
}
free(ctx->x86_pv.restore.vcpus);
--
generated by git-patchbot for /home/xen/git/xen.git#staging
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