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. Signed-off-by: Andrew Cooper <[email protected]> --- CC: Ian Jackson <[email protected]> CC: Wei Liu <[email protected]> --- tools/libxc/xc_sr_common.h | 45 ++++++++++++++++++++----- tools/libxc/xc_sr_restore_x86_hvm.c | 21 ++++-------- tools/libxc/xc_sr_restore_x86_pv.c | 67 ++++++++++++++----------------------- 3 files changed, 68 insertions(+), 65 deletions(-) diff --git a/tools/libxc/xc_sr_common.h b/tools/libxc/xc_sr_common.h index b66d785e50..19b053911f 100644 --- a/tools/libxc/xc_sr_common.h +++ b/tools/libxc/xc_sr_common.h @@ -165,13 +165,40 @@ 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; + + memcpy(ptr, src, size); + + free(blob->ptr); + blob->ptr = memcpy(ptr, src, size); + blob->size = size; + + return 0; +} + struct xc_sr_context { xc_interface *xch; @@ -306,8 +333,11 @@ 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 int nr_vcpus; } restore; }; @@ -327,8 +357,7 @@ 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 c0598af8b7..0ec506632a 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 int 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 ) @@ -738,7 +738,7 @@ 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; int rc = -1; switch ( rec->type ) @@ -812,6 +812,7 @@ 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; } @@ -822,6 +823,7 @@ 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: @@ -831,6 +833,7 @@ 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: @@ -840,34 +843,14 @@ 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; @@ -1159,10 +1142,10 @@ 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); -- 2.11.0 _______________________________________________ Xen-devel mailing list [email protected] https://lists.xenproject.org/mailman/listinfo/xen-devel
