From 770d1e858de56ba8f2e0d7e45c08f48d599528e5 Mon Sep 17 00:00:00 2001 From: Tim Deegan Date: Thu, 8 Mar 2012 16:40:05 +0000 Subject: Use a reserved pfn in the guest address space to store mem event rings This solves a long-standing issue in which the pages backing these rings were pages belonging to dom0 user-space processes. Thus, if the process would die unexpectedly, Xen would keep posting events to a page now belonging to some other process. We update all API-consumers in tree (xenpaging and xen-access). This is an API/ABI change, so please speak up if it breaks your accumptions. The patch touches tools, hypervisor x86/hvm bits, and hypervisor x86/mm bits. Signed-off-by: Andres Lagar-Cavilla Acked-by: Tim Deegan Acked-by: Ian Campbell Committed-by: Tim Deegan --- tools/libxc/xc_domain_restore.c | 42 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) (limited to 'tools/libxc/xc_domain_restore.c') diff --git a/tools/libxc/xc_domain_restore.c b/tools/libxc/xc_domain_restore.c index 06bea86718..3e4d5183a5 100644 --- a/tools/libxc/xc_domain_restore.c +++ b/tools/libxc/xc_domain_restore.c @@ -677,6 +677,9 @@ typedef struct { int max_vcpu_id; uint64_t vcpumap; uint64_t identpt; + uint64_t paging_ring_pfn; + uint64_t access_ring_pfn; + uint64_t sharing_ring_pfn; uint64_t vm86_tss; uint64_t console_pfn; uint64_t acpi_ioport_location; @@ -750,6 +753,39 @@ static int pagebuf_get_one(xc_interface *xch, struct restore_ctx *ctx, // DPRINTF("EPT identity map address: %llx\n", buf->identpt); return pagebuf_get_one(xch, ctx, buf, fd, dom); + case XC_SAVE_ID_HVM_PAGING_RING_PFN: + /* Skip padding 4 bytes then read the paging ring location. */ + if ( RDEXACT(fd, &buf->paging_ring_pfn, sizeof(uint32_t)) || + RDEXACT(fd, &buf->paging_ring_pfn, sizeof(uint64_t)) ) + { + PERROR("error read the paging ring pfn"); + return -1; + } + // DPRINTF("paging ring pfn address: %llx\n", buf->paging_ring_pfn); + return pagebuf_get_one(xch, ctx, buf, fd, dom); + + case XC_SAVE_ID_HVM_ACCESS_RING_PFN: + /* Skip padding 4 bytes then read the mem access ring location. */ + if ( RDEXACT(fd, &buf->access_ring_pfn, sizeof(uint32_t)) || + RDEXACT(fd, &buf->access_ring_pfn, sizeof(uint64_t)) ) + { + PERROR("error read the access ring pfn"); + return -1; + } + // DPRINTF("access ring pfn address: %llx\n", buf->access_ring_pfn); + return pagebuf_get_one(xch, ctx, buf, fd, dom); + + case XC_SAVE_ID_HVM_SHARING_RING_PFN: + /* Skip padding 4 bytes then read the sharing ring location. */ + if ( RDEXACT(fd, &buf->sharing_ring_pfn, sizeof(uint32_t)) || + RDEXACT(fd, &buf->sharing_ring_pfn, sizeof(uint64_t)) ) + { + PERROR("error read the sharing ring pfn"); + return -1; + } + // DPRINTF("sharing ring pfn address: %llx\n", buf->sharing_ring_pfn); + return pagebuf_get_one(xch, ctx, buf, fd, dom); + case XC_SAVE_ID_HVM_VM86_TSS: /* Skip padding 4 bytes then read the vm86 TSS location. */ if ( RDEXACT(fd, &buf->vm86_tss, sizeof(uint32_t)) || @@ -1460,6 +1496,12 @@ int xc_domain_restore(xc_interface *xch, int io_fd, uint32_t dom, /* should this be deferred? does it change? */ if ( pagebuf.identpt ) xc_set_hvm_param(xch, dom, HVM_PARAM_IDENT_PT, pagebuf.identpt); + if ( pagebuf.paging_ring_pfn ) + xc_set_hvm_param(xch, dom, HVM_PARAM_PAGING_RING_PFN, pagebuf.paging_ring_pfn); + if ( pagebuf.access_ring_pfn ) + xc_set_hvm_param(xch, dom, HVM_PARAM_ACCESS_RING_PFN, pagebuf.access_ring_pfn); + if ( pagebuf.sharing_ring_pfn ) + xc_set_hvm_param(xch, dom, HVM_PARAM_SHARING_RING_PFN, pagebuf.sharing_ring_pfn); if ( pagebuf.vm86_tss ) xc_set_hvm_param(xch, dom, HVM_PARAM_VM86_TSS, pagebuf.vm86_tss); if ( pagebuf.console_pfn ) -- cgit v1.2.3