diff options
Diffstat (limited to 'sysutils/xen-tools/files/xsa153-libxl.patch')
| -rw-r--r-- | sysutils/xen-tools/files/xsa153-libxl.patch | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/sysutils/xen-tools/files/xsa153-libxl.patch b/sysutils/xen-tools/files/xsa153-libxl.patch new file mode 100644 index 000000000000..14a50eb02ee4 --- /dev/null +++ b/sysutils/xen-tools/files/xsa153-libxl.patch @@ -0,0 +1,86 @@ +From 27593ec62bdad8621df910931349d964a6dbaa8c Mon Sep 17 00:00:00 2001 +From: Ian Jackson <ian.jackson@eu.citrix.com> +Date: Wed, 21 Oct 2015 16:18:30 +0100 +Subject: [PATCH XSA-153 v3] libxl: adjust PoD target by memory fudge, too + +PoD guests need to balloon at least as far as required by PoD, or risk +crashing. Currently they don't necessarily know what the right value +is, because our memory accounting is (at the very least) confusing. + +Apply the memory limit fudge factor to the in-hypervisor PoD memory +target, too. This will increase the size of the guest's PoD cache by +the fudge factor LIBXL_MAXMEM_CONSTANT (currently 1Mby). This ensures +that even with a slightly-off balloon driver, the guest will be +stable even under memory pressure. + +There are two call sites of xc_domain_set_pod_target that need fixing: + +The one in libxl_set_memory_target is straightforward. + +The one in xc_hvm_build_x86.c:setup_guest is more awkward. Simply +setting the PoD target differently does not work because the various +amounts of memory during domain construction no longer match up. +Instead, we adjust the guest memory target in xenstore (but only for +PoD guests). + +This introduces a 1Mby discrepancy between the balloon target of a PoD +guest at boot, and the target set by an apparently-equivalent `xl +mem-set' (or similar) later. This approach is low-risk for a security +fix but we need to fix this up properly in xen.git#staging and +probably also in stable trees. + +This is XSA-153. + +Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com> +--- + tools/libxl/libxl.c | 2 +- + tools/libxl/libxl_dom.c | 9 ++++++++- + 2 files changed, 9 insertions(+), 2 deletions(-) + +diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c +index d38d0c7..1366177 100644 +--- a/tools/libxl/libxl.c ++++ b/tools/libxl/libxl.c +@@ -4815,7 +4815,7 @@ retry_transaction: + } + + rc = xc_domain_set_pod_target(ctx->xch, domid, +- new_target_memkb / 4, NULL, NULL, NULL); ++ (new_target_memkb + LIBXL_MAXMEM_CONSTANT) / 4, NULL, NULL, NULL); + if (rc != 0) { + LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, + "xc_domain_set_pod_target domid=%d, memkb=%d " +diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c +index b514377..8019f4e 100644 +--- a/tools/libxl/libxl_dom.c ++++ b/tools/libxl/libxl_dom.c +@@ -486,6 +486,7 @@ int libxl__build_post(libxl__gc *gc, uint32_t domid, + xs_transaction_t t; + char **ents; + int i, rc; ++ int64_t mem_target_fudge; + + if (info->num_vnuma_nodes && !info->num_vcpu_soft_affinity) { + rc = set_vnuma_affinity(gc, domid, info); +@@ -518,11 +519,17 @@ int libxl__build_post(libxl__gc *gc, uint32_t domid, + } + } + ++ mem_target_fudge = ++ (info->type == LIBXL_DOMAIN_TYPE_HVM && ++ info->max_memkb > info->target_memkb) ++ ? LIBXL_MAXMEM_CONSTANT : 0; ++ + ents = libxl__calloc(gc, 12 + (info->max_vcpus * 2) + 2, sizeof(char *)); + ents[0] = "memory/static-max"; + ents[1] = GCSPRINTF("%"PRId64, info->max_memkb); + ents[2] = "memory/target"; +- ents[3] = GCSPRINTF("%"PRId64, info->target_memkb - info->video_memkb); ++ ents[3] = GCSPRINTF("%"PRId64, info->target_memkb - info->video_memkb ++ - mem_target_fudge); + ents[4] = "memory/videoram"; + ents[5] = GCSPRINTF("%"PRId64, info->video_memkb); + ents[6] = "domid"; +-- +1.7.10.4 + |