From e7265739e0db957176261236be53c0c270c2efa1 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Thu, 18 Mar 2021 14:26:24 +0100 Subject: [PATCH] tools/libs/ctrl: fix xc_core_arch_map_p2m() to support linear p2m table The core of a pv linux guest produced via "xl dump-core" is nor usable as since kernel 4.14 only the linear p2m table is kept if Xen indicates it is supporting that. Unfortunately xc_core_arch_map_p2m() is still supporting the 3-level p2m tree only. Fix that by copying the functionality of map_p2m() from libxenguest to libxenctrl. Fixes: dc6d60937121 ("libxc: set flag for support of linear p2m list in domain builder") Signed-off-by: Juergen Gross --- This is a backport candidate. --- tools/libs/ctrl/xc_core_x86.c | 235 ++++++++++++++++++++++++++++++---- tools/libs/ctrl/xc_private.h | 1 + 2 files changed, 208 insertions(+), 28 deletions(-) diff --git a/tools/libs/ctrl/xc_core_x86.c b/tools/libs/ctrl/xc_core_x86.c index cb76e6207b..a8806efb4a 100644 --- a/tools/libs/ctrl/xc_core_x86.c +++ b/tools/libs/ctrl/xc_core_x86.c @@ -17,6 +17,7 @@ * */ +#include #include "xc_private.h" #include "xc_core.h" #include @@ -65,34 +66,169 @@ xc_core_arch_memory_map_get(xc_interface *xch, struct xc_core_arch_context *unus return 0; } -static int -xc_core_arch_map_p2m_rw(xc_interface *xch, struct domain_info_context *dinfo, xc_dominfo_t *info, - shared_info_any_t *live_shinfo, xen_pfn_t **live_p2m, - unsigned long *pfnp, int rw) +static inline bool is_canonical_address(uint64_t vaddr) { - /* Double and single indirect references to the live P2M table */ - xen_pfn_t *live_p2m_frame_list_list = NULL; - xen_pfn_t *live_p2m_frame_list = NULL; - /* Copies of the above. */ - xen_pfn_t *p2m_frame_list_list = NULL; - xen_pfn_t *p2m_frame_list = NULL; + return ((int64_t)vaddr >> 47) == ((int64_t)vaddr >> 63); +} - uint32_t dom = info->domid; - int ret = -1; - int err; - int i; +/* Virtual address ranges reserved for hypervisor. */ +#define HYPERVISOR_VIRT_START_X86_64 0xFFFF800000000000ULL +#define HYPERVISOR_VIRT_END_X86_64 0xFFFF87FFFFFFFFFFULL - if ( xc_domain_nr_gpfns(xch, info->domid, &dinfo->p2m_size) < 0 ) +#define HYPERVISOR_VIRT_START_X86_32 0x00000000F5800000ULL +#define HYPERVISOR_VIRT_END_X86_32 0x00000000FFFFFFFFULL + +static xen_pfn_t * +xc_core_arch_map_p2m_list_rw(xc_interface *xch, struct domain_info_context *dinfo, + uint32_t dom, shared_info_any_t *live_shinfo, + uint64_t p2m_cr3) +{ + uint64_t p2m_vaddr, p2m_end, mask, off; + xen_pfn_t p2m_mfn, mfn, saved_mfn, max_pfn; + uint64_t *ptes = NULL; + xen_pfn_t *mfns = NULL; + unsigned int fpp, n_pages, level, n_levels, shift, + idx_start, idx_end, idx, saved_idx; + + p2m_vaddr = GET_FIELD(live_shinfo, arch.p2m_vaddr, dinfo->guest_width); + fpp = PAGE_SIZE / dinfo->guest_width; + dinfo->p2m_frames = (dinfo->p2m_size - 1) / fpp + 1; + p2m_end = p2m_vaddr + dinfo->p2m_frames * PAGE_SIZE - 1; + + if ( dinfo->guest_width == 8 ) { - ERROR("Could not get maximum GPFN!"); - goto out; + mask = 0x0000ffffffffffffULL; + n_levels = 4; + p2m_mfn = p2m_cr3 >> 12; + if ( !is_canonical_address(p2m_vaddr) || + !is_canonical_address(p2m_end) || + p2m_end < p2m_vaddr || + (p2m_vaddr <= HYPERVISOR_VIRT_END_X86_64 && + p2m_end > HYPERVISOR_VIRT_START_X86_64) ) + { + ERROR("Bad virtual p2m address range %#" PRIx64 "-%#" PRIx64, + p2m_vaddr, p2m_end); + errno = ERANGE; + goto out; + } + } + else + { + mask = 0x00000000ffffffffULL; + n_levels = 3; + if ( p2m_cr3 & ~mask ) + p2m_mfn = ~0UL; + else + p2m_mfn = (uint32_t)((p2m_cr3 >> 12) | (p2m_cr3 << 20)); + if ( p2m_vaddr > mask || p2m_end > mask || p2m_end < p2m_vaddr || + (p2m_vaddr <= HYPERVISOR_VIRT_END_X86_32 && + p2m_end > HYPERVISOR_VIRT_START_X86_32) ) + { + ERROR("Bad virtual p2m address range %#" PRIx64 "-%#" PRIx64, + p2m_vaddr, p2m_end); + errno = ERANGE; + goto out; + } } - if ( dinfo->p2m_size < info->nr_pages ) + mfns = malloc(sizeof(*mfns)); + if ( !mfns ) { - ERROR("p2m_size < nr_pages -1 (%lx < %lx", dinfo->p2m_size, info->nr_pages - 1); + ERROR("Cannot allocate memory for array of %u mfns", 1); goto out; } + mfns[0] = p2m_mfn; + off = 0; + saved_mfn = 0; + idx_start = idx_end = saved_idx = 0; + + for ( level = n_levels; level > 0; level-- ) + { + n_pages = idx_end - idx_start + 1; + ptes = xc_map_foreign_pages(xch, dom, PROT_READ, mfns, n_pages); + if ( !ptes ) + { + PERROR("Failed to map %u page table pages for p2m list", n_pages); + goto out; + } + free(mfns); + + shift = level * 9 + 3; + idx_start = ((p2m_vaddr - off) & mask) >> shift; + idx_end = ((p2m_end - off) & mask) >> shift; + idx = idx_end - idx_start + 1; + mfns = malloc(sizeof(*mfns) * idx); + if ( !mfns ) + { + ERROR("Cannot allocate memory for array of %u mfns", idx); + goto out; + } + + for ( idx = idx_start; idx <= idx_end; idx++ ) + { + mfn = (ptes[idx] & 0x000ffffffffff000ULL) >> PAGE_SHIFT; + if ( mfn == 0 ) + { + ERROR("Bad mfn %#lx during page table walk for vaddr %#" PRIx64 " at level %d of p2m list", + mfn, off + ((uint64_t)idx << shift), level); + errno = ERANGE; + goto out; + } + mfns[idx - idx_start] = mfn; + + /* Maximum pfn check at level 2. Same reasoning as for p2m tree. */ + if ( level == 2 ) + { + if ( mfn != saved_mfn ) + { + saved_mfn = mfn; + saved_idx = idx - idx_start; + } + } + } + + if ( level == 2 ) + { + if ( saved_idx == idx_end ) + saved_idx++; + max_pfn = ((xen_pfn_t)saved_idx << 9) * fpp; + if ( max_pfn < dinfo->p2m_size ) + { + dinfo->p2m_size = max_pfn; + dinfo->p2m_frames = (dinfo->p2m_size + fpp - 1) / fpp; + p2m_end = p2m_vaddr + dinfo->p2m_frames * PAGE_SIZE - 1; + idx_end = idx_start + saved_idx; + } + } + + munmap(ptes, n_pages * PAGE_SIZE); + ptes = NULL; + off = p2m_vaddr & ((mask >> shift) << shift); + } + + return mfns; + + out: + free(mfns); + if ( ptes ) + munmap(ptes, n_pages * PAGE_SIZE); + + return NULL; +} + +static xen_pfn_t * +xc_core_arch_map_p2m_tree_rw(xc_interface *xch, struct domain_info_context *dinfo, + uint32_t dom, shared_info_any_t *live_shinfo) +{ + /* Double and single indirect references to the live P2M table */ + xen_pfn_t *live_p2m_frame_list_list; + xen_pfn_t *live_p2m_frame_list = NULL; + /* Copies of the above. */ + xen_pfn_t *p2m_frame_list_list = NULL; + xen_pfn_t *p2m_frame_list; + + int err; + int i; live_p2m_frame_list_list = xc_map_foreign_range(xch, dom, PAGE_SIZE, PROT_READ, @@ -151,10 +287,61 @@ xc_core_arch_map_p2m_rw(xc_interface *xch, struct domain_info_context *dinfo, xc for ( i = P2M_FL_ENTRIES - 1; i >= 0; i-- ) p2m_frame_list[i] = ((uint32_t *)p2m_frame_list)[i]; + dinfo->p2m_frames = P2M_FL_ENTRIES; + + return p2m_frame_list; + + out: + err = errno; + + if ( live_p2m_frame_list_list ) + munmap(live_p2m_frame_list_list, PAGE_SIZE); + + if ( live_p2m_frame_list ) + munmap(live_p2m_frame_list, P2M_FLL_ENTRIES * PAGE_SIZE); + + free(p2m_frame_list_list); + + errno = err; + + return NULL; +} + +static int +xc_core_arch_map_p2m_rw(xc_interface *xch, struct domain_info_context *dinfo, xc_dominfo_t *info, + shared_info_any_t *live_shinfo, xen_pfn_t **live_p2m, + unsigned long *pfnp, int rw) +{ + xen_pfn_t *p2m_frame_list = NULL; + uint64_t p2m_cr3; + uint32_t dom = info->domid; + int ret = -1; + int err; + + if ( xc_domain_nr_gpfns(xch, info->domid, &dinfo->p2m_size) < 0 ) + { + ERROR("Could not get maximum GPFN!"); + goto out; + } + + if ( dinfo->p2m_size < info->nr_pages ) + { + ERROR("p2m_size < nr_pages -1 (%lx < %lx", dinfo->p2m_size, info->nr_pages - 1); + goto out; + } + + p2m_cr3 = GET_FIELD(live_shinfo, arch.p2m_cr3, dinfo->guest_width); + + p2m_frame_list = p2m_cr3 ? xc_core_arch_map_p2m_list_rw(xch, dinfo, dom, live_shinfo, p2m_cr3) + : xc_core_arch_map_p2m_tree_rw(xch, dinfo, dom, live_shinfo); + + if ( !p2m_frame_list ) + goto out; + *live_p2m = xc_map_foreign_pages(xch, dom, rw ? (PROT_READ | PROT_WRITE) : PROT_READ, p2m_frame_list, - P2M_FL_ENTRIES); + dinfo->p2m_frames); if ( !*live_p2m ) { @@ -169,14 +356,6 @@ xc_core_arch_map_p2m_rw(xc_interface *xch, struct domain_info_context *dinfo, xc out: err = errno; - if ( live_p2m_frame_list_list ) - munmap(live_p2m_frame_list_list, PAGE_SIZE); - - if ( live_p2m_frame_list ) - munmap(live_p2m_frame_list, P2M_FLL_ENTRIES * PAGE_SIZE); - - free(p2m_frame_list_list); - free(p2m_frame_list); errno = err; diff --git a/tools/libs/ctrl/xc_private.h b/tools/libs/ctrl/xc_private.h index f0b5f83ac8..8ebc0b59da 100644 --- a/tools/libs/ctrl/xc_private.h +++ b/tools/libs/ctrl/xc_private.h @@ -79,6 +79,7 @@ struct iovec { struct domain_info_context { unsigned int guest_width; + unsigned int p2m_frames; unsigned long p2m_size; }; -- 2.26.2