[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v4.2] libxc: Defer initialization of start_page for HVM guests
With commit 8c45adec18e0 ("libxc: create unmapped initrd in domain builder if supported") location of ramdisk may not be available to HVMlite guests by the time alloc_magic_pages_hvm() is invoked if the guest supports unmapped initrd. So let's move ramdisk info initialization (along with a few other operations that are not directly related to allocating magic/special pages) from alloc_magic_pages_hvm() to bootlate_hvm(). Since we now split allocation and mapping of the start_info segment let's stash it, along with cmdline length, in xc_dom_image so that we can check whether we are mapping correctly-sized range. We can also stop using xc_dom_image.start_info_pfn and leave it for PV(H) guests only. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> --- v4: * See the last two paragraphs from commit message above v4.1: * Inverted testing of start_info_size in bootlate_hvm(). v4.2 * <facepalm> Actually do what I said I'd do in 4.1 tools/libxc/include/xc_dom.h | 2 + tools/libxc/xc_dom_x86.c | 140 +++++++++++++++++++++++------------------ 2 files changed, 80 insertions(+), 62 deletions(-) diff --git a/tools/libxc/include/xc_dom.h b/tools/libxc/include/xc_dom.h index 2460818..cac4698 100644 --- a/tools/libxc/include/xc_dom.h +++ b/tools/libxc/include/xc_dom.h @@ -71,6 +71,7 @@ struct xc_dom_image { /* arguments and parameters */ char *cmdline; + size_t cmdline_size; uint32_t f_requested[XENFEAT_NR_SUBMAPS]; /* info from (elf) kernel image */ @@ -91,6 +92,7 @@ struct xc_dom_image { struct xc_dom_seg p2m_seg; struct xc_dom_seg pgtables_seg; struct xc_dom_seg devicetree_seg; + struct xc_dom_seg start_info_seg; /* HVMlite only */ xen_pfn_t start_info_pfn; xen_pfn_t console_pfn; xen_pfn_t xenstore_pfn; diff --git a/tools/libxc/xc_dom_x86.c b/tools/libxc/xc_dom_x86.c index b8d2904..edf2db1 100644 --- a/tools/libxc/xc_dom_x86.c +++ b/tools/libxc/xc_dom_x86.c @@ -586,23 +586,12 @@ static void build_hvm_info(void *hvm_info_page, struct xc_dom_image *dom) static int alloc_magic_pages_hvm(struct xc_dom_image *dom) { unsigned long i; - void *hvm_info_page; uint32_t *ident_pt, domid = dom->guest_domid; int rc; xen_pfn_t special_array[X86_HVM_NR_SPECIAL_PAGES]; xen_pfn_t ioreq_server_array[NR_IOREQ_SERVER_PAGES]; xc_interface *xch = dom->xch; - if ( dom->device_model ) - { - if ( (hvm_info_page = xc_map_foreign_range( - xch, domid, PAGE_SIZE, PROT_READ | PROT_WRITE, - HVM_INFO_PFN)) == NULL ) - goto error_out; - build_hvm_info(hvm_info_page, dom); - munmap(hvm_info_page, PAGE_SIZE); - } - /* Allocate and clear special pages. */ for ( i = 0; i < X86_HVM_NR_SPECIAL_PAGES; i++ ) special_array[i] = special_pfn(i); @@ -636,65 +625,25 @@ static int alloc_magic_pages_hvm(struct xc_dom_image *dom) if ( !dom->device_model ) { - struct xc_dom_seg seg; - struct hvm_start_info *start_info; - char *cmdline; - struct hvm_modlist_entry *modlist; - void *start_page; - size_t cmdline_size = 0; - size_t start_info_size = sizeof(*start_info); + size_t start_info_size = sizeof(struct hvm_start_info); if ( dom->cmdline ) { - cmdline_size = ROUNDUP(strlen(dom->cmdline) + 1, 8); - start_info_size += cmdline_size; - + dom->cmdline_size = ROUNDUP(strlen(dom->cmdline) + 1, 8); + start_info_size += dom->cmdline_size; } + + /* Limited to one module. */ if ( dom->ramdisk_blob ) - start_info_size += sizeof(*modlist); /* Limited to one module. */ + start_info_size += sizeof(struct hvm_modlist_entry); - rc = xc_dom_alloc_segment(dom, &seg, "HVMlite start info", 0, - start_info_size); + rc = xc_dom_alloc_segment(dom, &dom->start_info_seg, + "HVMlite start info", 0, start_info_size); if ( rc != 0 ) { DOMPRINTF("Unable to reserve memory for the start info"); goto out; } - - start_page = xc_map_foreign_range(xch, domid, start_info_size, - PROT_READ | PROT_WRITE, - seg.pfn); - if ( start_page == NULL ) - { - DOMPRINTF("Unable to map HVM start info page"); - goto error_out; - } - - start_info = start_page; - cmdline = start_page + sizeof(*start_info); - modlist = start_page + sizeof(*start_info) + cmdline_size; - - if ( dom->cmdline ) - { - strncpy(cmdline, dom->cmdline, cmdline_size); - start_info->cmdline_paddr = (seg.pfn << PAGE_SHIFT) + - ((uintptr_t)cmdline - (uintptr_t)start_info); - } - - if ( dom->ramdisk_blob ) - { - modlist[0].paddr = dom->ramdisk_seg.vstart - dom->parms.virt_base; - modlist[0].size = dom->ramdisk_seg.vend - dom->ramdisk_seg.vstart; - start_info->modlist_paddr = (seg.pfn << PAGE_SHIFT) + - ((uintptr_t)modlist - (uintptr_t)start_info); - start_info->nr_modules = 1; - } - - start_info->magic = HVM_START_MAGIC_VALUE; - - munmap(start_page, start_info_size); - - dom->start_info_pfn = seg.pfn; } else { @@ -1095,8 +1044,8 @@ static int vcpu_hvm(struct xc_dom_image *dom) /* Set the IP. */ bsp_ctx.cpu.rip = dom->parms.phys_entry; - if ( dom->start_info_pfn ) - bsp_ctx.cpu.rbx = dom->start_info_pfn << PAGE_SHIFT; + if ( dom->start_info_seg.pfn ) + bsp_ctx.cpu.rbx = dom->start_info_seg.pfn << PAGE_SHIFT; /* Set the end descriptor. */ bsp_ctx.end_d.typecode = HVM_SAVE_CODE(END); @@ -1783,7 +1732,74 @@ static int alloc_pgtables_hvm(struct xc_dom_image *dom) static int bootlate_hvm(struct xc_dom_image *dom) { - DOMPRINTF("%s: doing nothing", __func__); + uint32_t domid = dom->guest_domid; + xc_interface *xch = dom->xch; + + if ( !dom->device_model ) + { + struct hvm_start_info *start_info; + size_t start_info_size; + void *start_page; + + start_info_size = sizeof(*start_info) + dom->cmdline_size; + if ( dom->ramdisk_blob ) + start_info_size += sizeof(struct hvm_modlist_entry); + + if ( start_info_size > + dom->start_info_seg.pages << XC_DOM_PAGE_SHIFT(dom) ) + { + DOMPRINTF("Trying to map beyond start_info_seg"); + return -1; + } + + start_page = xc_map_foreign_range(xch, domid, start_info_size, + PROT_READ | PROT_WRITE, + dom->start_info_seg.pfn); + if ( start_page == NULL ) + { + DOMPRINTF("Unable to map HVM start info page"); + return -1; + } + + start_info = start_page; + + if ( dom->cmdline ) + { + char *cmdline = start_page + sizeof(*start_info); + + strncpy(cmdline, dom->cmdline, dom->cmdline_size); + start_info->cmdline_paddr = (dom->start_info_seg.pfn << PAGE_SHIFT) + + ((uintptr_t)cmdline - (uintptr_t)start_info); + } + + if ( dom->ramdisk_blob ) + { + struct hvm_modlist_entry *modlist = + start_page + sizeof(*start_info) + dom->cmdline_size; + + modlist[0].paddr = dom->ramdisk_seg.vstart - dom->parms.virt_base; + modlist[0].size = dom->ramdisk_seg.vend - dom->ramdisk_seg.vstart; + start_info->modlist_paddr = (dom->start_info_seg.pfn << PAGE_SHIFT) + + ((uintptr_t)modlist - (uintptr_t)start_info); + start_info->nr_modules = 1; + } + + start_info->magic = HVM_START_MAGIC_VALUE; + + munmap(start_page, start_info_size); + } + else + { + void *hvm_info_page; + + if ( (hvm_info_page = xc_map_foreign_range( + xch, domid, PAGE_SIZE, PROT_READ | PROT_WRITE, + HVM_INFO_PFN)) == NULL ) + return -1; + build_hvm_info(hvm_info_page, dom); + munmap(hvm_info_page, PAGE_SIZE); + } + return 0; } -- 1.7.1 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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