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[Xen-devel] [PATCH v5 23/28] libxc: allow creating domains without emulated devices.

From: Roger Pau Monne <roger.pau@xxxxxxxxxx>

Date: Fri, 21 Aug 2015 18:53:36 +0200

Cc: Wei Liu <wei.liu2@xxxxxxxxxx>, Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>, Ian Jackson <ian.jackson@xxxxxxxxxxxxx>, Ian Campbell <ian.campbell@xxxxxxxxxx>, Roger Pau Monne <roger.pau@xxxxxxxxxx>

Delivery-date: Fri, 21 Aug 2015 17:15:28 +0000

List-id: Xen developer discussion <xen-devel.lists.xen.org>

Introduce a new flag in xc_dom_image that turns on and off the emulated devices. This prevents creating the VGA hole, the hvm_info page and the ioreq server pages. libxl unconditionally sets it to true for all HVM domains at the moment. Signed-off-by: Roger Pau MonnÃ <roger.pau@xxxxxxxxxx> Acked-by: Wei Liu <wei.liu2@xxxxxxxxxx> Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx> Cc: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx> Cc: Ian Campbell <ian.campbell@xxxxxxxxxx> Cc: Wei Liu <wei.liu2@xxxxxxxxxx> --- Changes since v4: - Store the size of the VGA hole inside of the xc_dom_image struct and set it from libxl. - Rename dom->emulation to dom->device_model (no functional change). - Add Wei Liu Acked-by. Changes since v3: - Explain the meaning of the "emulation" xc_dom_image field. --- tools/libxc/include/xc_dom.h | 4 +++ tools/libxc/xc_dom_x86.c | 73 ++++++++++++++++++++++++-------------------- tools/libxl/libxl_dom.c | 2 ++ tools/libxl/libxl_internal.h | 1 + 4 files changed, 47 insertions(+), 33 deletions(-) diff --git a/tools/libxc/include/xc_dom.h b/tools/libxc/include/xc_dom.h index cda40d9..507b323 100644 --- a/tools/libxc/include/xc_dom.h +++ b/tools/libxc/include/xc_dom.h @@ -193,6 +193,10 @@ struct xc_dom_image { xen_pfn_t mmio_size; xen_pfn_t lowmem_end; xen_pfn_t highmem_end; + xen_pfn_t vga_hole_size; + + /* If unset disables the setup of the IOREQ pages. */ + bool device_model; /* Extra ACPI tables passed to HVMLOADER */ struct xc_hvm_firmware_module acpi_module; diff --git a/tools/libxc/xc_dom_x86.c b/tools/libxc/xc_dom_x86.c index 0a4ac58..fb71717 100644 --- a/tools/libxc/xc_dom_x86.c +++ b/tools/libxc/xc_dom_x86.c @@ -49,8 +49,6 @@ #define X86_CR0_PE 0x01 #define X86_CR0_ET 0x10 -#define VGA_HOLE_SIZE (0x20) - #define SPECIALPAGE_PAGING 0 #define SPECIALPAGE_ACCESS 1 #define SPECIALPAGE_SHARING 2 @@ -522,12 +520,15 @@ static int alloc_magic_pages_hvm(struct xc_dom_image *dom) xen_pfn_t ioreq_server_array[NR_IOREQ_SERVER_PAGES]; xc_interface *xch = dom->xch; - 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); + 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 < NR_SPECIAL_PAGES; i++ ) @@ -559,30 +560,33 @@ static int alloc_magic_pages_hvm(struct xc_dom_image *dom) xc_hvm_param_set(xch, domid, HVM_PARAM_SHARING_RING_PFN, special_pfn(SPECIALPAGE_SHARING)); - /* - * Allocate and clear additional ioreq server pages. The default - * server will use the IOREQ and BUFIOREQ special pages above. - */ - for ( i = 0; i < NR_IOREQ_SERVER_PAGES; i++ ) - ioreq_server_array[i] = ioreq_server_pfn(i); - - rc = xc_domain_populate_physmap_exact(xch, domid, NR_IOREQ_SERVER_PAGES, 0, - 0, ioreq_server_array); - if ( rc != 0 ) + if ( dom->device_model ) { - DOMPRINTF("Could not allocate ioreq server pages."); - goto error_out; - } + /* + * Allocate and clear additional ioreq server pages. The default + * server will use the IOREQ and BUFIOREQ special pages above. + */ + for ( i = 0; i < NR_IOREQ_SERVER_PAGES; i++ ) + ioreq_server_array[i] = ioreq_server_pfn(i); - if ( xc_clear_domain_pages(xch, domid, ioreq_server_pfn(0), - NR_IOREQ_SERVER_PAGES) ) + rc = xc_domain_populate_physmap_exact(xch, domid, NR_IOREQ_SERVER_PAGES, 0, + 0, ioreq_server_array); + if ( rc != 0 ) + { + DOMPRINTF("Could not allocate ioreq server pages."); goto error_out; + } - /* Tell the domain where the pages are and how many there are */ - xc_hvm_param_set(xch, domid, HVM_PARAM_IOREQ_SERVER_PFN, - ioreq_server_pfn(0)); - xc_hvm_param_set(xch, domid, HVM_PARAM_NR_IOREQ_SERVER_PAGES, - NR_IOREQ_SERVER_PAGES); + if ( xc_clear_domain_pages(xch, domid, ioreq_server_pfn(0), + NR_IOREQ_SERVER_PAGES) ) + goto error_out; + + /* Tell the domain where the pages are and how many there are */ + xc_hvm_param_set(xch, domid, HVM_PARAM_IOREQ_SERVER_PFN, + ioreq_server_pfn(0)); + xc_hvm_param_set(xch, domid, HVM_PARAM_NR_IOREQ_SERVER_PAGES, + NR_IOREQ_SERVER_PAGES); + } /* * Identity-map page table is required for running with CR0.PG=0 when @@ -1319,7 +1323,8 @@ static int meminit_hvm(struct xc_dom_image *dom) * allocated is pointless. */ if ( claim_enabled ) { - rc = xc_domain_claim_pages(xch, domid, target_pages - VGA_HOLE_SIZE); + rc = xc_domain_claim_pages(xch, domid, + target_pages - dom->vga_hole_size); if ( rc != 0 ) { DOMPRINTF("Could not allocate memory for HVM guest as we cannot claim memory!"); @@ -1335,7 +1340,8 @@ static int meminit_hvm(struct xc_dom_image *dom) * tot_pages will be target_pages - VGA_HOLE_SIZE after * this call. */ - rc = xc_domain_set_pod_target(xch, domid, target_pages - VGA_HOLE_SIZE, + rc = xc_domain_set_pod_target(xch, domid, + target_pages - dom->vga_hole_size, NULL, NULL, NULL); if ( rc != 0 ) { @@ -1354,8 +1360,9 @@ static int meminit_hvm(struct xc_dom_image *dom) * Under 2MB mode, we allocate pages in batches of no more than 8MB to * ensure that we can be preempted and hence dom0 remains responsive. */ - rc = xc_domain_populate_physmap_exact( - xch, domid, 0xa0, 0, memflags, &dom->p2m_host[0x00]); + if ( dom->device_model ) + rc = xc_domain_populate_physmap_exact( + xch, domid, 0xa0, 0, memflags, &dom->p2m_host[0x00]); stat_normal_pages = 0; for ( vmemid = 0; vmemid < nr_vmemranges; vmemid++ ) @@ -1374,7 +1381,7 @@ static int meminit_hvm(struct xc_dom_image *dom) * 0xA0000-0xC0000. Note that 0x00000-0xA0000 is populated just * before this loop. */ - if ( vmemranges[vmemid].start == 0 ) + if ( vmemranges[vmemid].start == 0 && dom->device_model ) { cur_pages = 0xc0; stat_normal_pages += 0xc0; diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c index d2cf9e3..4a214e7 100644 --- a/tools/libxl/libxl_dom.c +++ b/tools/libxl/libxl_dom.c @@ -987,6 +987,8 @@ int libxl__build_hvm(libxl__gc *gc, uint32_t domid, dom->lowmem_end = lowmem_end; dom->highmem_end = highmem_end; dom->mmio_start = mmio_start; + dom->vga_hole_size = LIBXL_VGA_HOLE_SIZE + dom->device_model = true; rc = libxl__domain_device_construct_rdm(gc, d_config, info->u.hvm.rdm_mem_boundary_memkb*1024, diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h index ea89f1f..294d442 100644 --- a/tools/libxl/libxl_internal.h +++ b/tools/libxl/libxl_internal.h @@ -100,6 +100,7 @@ #define LIBXL_HVM_EXTRA_MEMORY 2048 #define LIBXL_MIN_DOM0_MEM (128*1024) #define LIBXL_INVALID_GFN (~(uint64_t)0) +#define LIBXL_VGA_HOLE_SIZE 0x20 /* use 0 as the domid of the toolstack domain for now */ #define LIBXL_TOOLSTACK_DOMID 0 #define QEMU_SIGNATURE "DeviceModelRecord0002" -- 1.9.5 (Apple Git-50.3) _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel

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