From f36c8d0c957ba7f971d992f104b9984547e8429b Mon Sep 17 00:00:00 2001 From: Ian Campbell Date: Fri, 22 Oct 2010 15:14:51 +0100 Subject: [PATCH] libxc: do not align/lock buffers which do not need it On restore: region_mfn is passed to xc_map_foreign_range and xc_map_foreign_bulk. In both cases the buffer is accessed from the ioctl handler in the kernel and not from any hypercall. Therefore normal copy_{to,from}_user handling in the kernel will cope with any faulting access. p2m_batch is passed to xc_domain_memory_populate_physmap which takes care of bouncing the buffer already. On save: pfn_type is passed to xc_map_foreign_bulk which does not need locking as per region_mfn above. Signed-off-by: Ian Campbell Signed-off-by: Ian Jackson --- tools/libxc/xc_domain_restore.c | 18 ++---------------- tools/libxc/xc_domain_save.c | 9 +-------- 2 files changed, 3 insertions(+), 24 deletions(-) diff --git a/tools/libxc/xc_domain_restore.c b/tools/libxc/xc_domain_restore.c index 047cd774a7..5ac2de5445 100644 --- a/tools/libxc/xc_domain_restore.c +++ b/tools/libxc/xc_domain_restore.c @@ -1172,10 +1172,8 @@ int xc_domain_restore(xc_interface *xch, int io_fd, uint32_t dom, ctx->p2m = calloc(dinfo->p2m_size, sizeof(xen_pfn_t)); pfn_type = calloc(dinfo->p2m_size, sizeof(unsigned long)); - region_mfn = xc_memalign(PAGE_SIZE, ROUNDUP( - MAX_BATCH_SIZE * sizeof(xen_pfn_t), PAGE_SHIFT)); - ctx->p2m_batch = xc_memalign( - PAGE_SIZE, ROUNDUP(MAX_BATCH_SIZE * sizeof(xen_pfn_t), PAGE_SHIFT)); + region_mfn = malloc(ROUNDUP(MAX_BATCH_SIZE * sizeof(xen_pfn_t), PAGE_SHIFT)); + ctx->p2m_batch = malloc(ROUNDUP(MAX_BATCH_SIZE * sizeof(xen_pfn_t), PAGE_SHIFT)); if ( (ctx->p2m == NULL) || (pfn_type == NULL) || (region_mfn == NULL) || (ctx->p2m_batch == NULL) ) @@ -1190,18 +1188,6 @@ int xc_domain_restore(xc_interface *xch, int io_fd, uint32_t dom, memset(ctx->p2m_batch, 0, ROUNDUP(MAX_BATCH_SIZE * sizeof(xen_pfn_t), PAGE_SHIFT)); - if ( lock_pages(xch, region_mfn, sizeof(xen_pfn_t) * MAX_BATCH_SIZE) ) - { - PERROR("Could not lock region_mfn"); - goto out; - } - - if ( lock_pages(xch, ctx->p2m_batch, sizeof(xen_pfn_t) * MAX_BATCH_SIZE) ) - { - ERROR("Could not lock p2m_batch"); - goto out; - } - /* Get the domain's shared-info frame. */ domctl.cmd = XEN_DOMCTL_getdomaininfo; domctl.domain = (domid_t)dom; diff --git a/tools/libxc/xc_domain_save.c b/tools/libxc/xc_domain_save.c index 8dc08e0003..1f3022cd43 100644 --- a/tools/libxc/xc_domain_save.c +++ b/tools/libxc/xc_domain_save.c @@ -1071,8 +1071,7 @@ int xc_domain_save(xc_interface *xch, int io_fd, uint32_t dom, uint32_t max_iter analysis_phase(xch, dom, ctx, HYPERCALL_BUFFER(to_skip), 0); - pfn_type = xc_memalign(PAGE_SIZE, ROUNDUP( - MAX_BATCH_SIZE * sizeof(*pfn_type), PAGE_SHIFT)); + pfn_type = malloc(ROUNDUP(MAX_BATCH_SIZE * sizeof(*pfn_type), PAGE_SHIFT)); pfn_batch = calloc(MAX_BATCH_SIZE, sizeof(*pfn_batch)); pfn_err = malloc(MAX_BATCH_SIZE * sizeof(*pfn_err)); if ( (pfn_type == NULL) || (pfn_batch == NULL) || (pfn_err == NULL) ) @@ -1084,12 +1083,6 @@ int xc_domain_save(xc_interface *xch, int io_fd, uint32_t dom, uint32_t max_iter memset(pfn_type, 0, ROUNDUP(MAX_BATCH_SIZE * sizeof(*pfn_type), PAGE_SHIFT)); - if ( lock_pages(xch, pfn_type, MAX_BATCH_SIZE * sizeof(*pfn_type)) ) - { - PERROR("Unable to lock pfn_type array"); - goto out; - } - /* Setup the mfn_to_pfn table mapping */ if ( !(ctx->live_m2p = xc_map_m2p(xch, ctx->max_mfn, PROT_READ, &ctx->m2p_mfn0)) ) { -- 2.30.2