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xen/tools/libs/guest/xg_sr_save_x86_pv.c
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Alejandro Vallejo 3b5201e8cf tools: Use new xc function for some xc_domain_getinfo() calls 
Move calls that require a information about a single precisely identified
domain to the new xc_domain_getinfo_single().

Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
2023-05-10 19:59:27 +01:00

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#include <assert.h>
#include <limits.h>
#include "xg_sr_common_x86_pv.h"
/* Check a 64 bit virtual address for being canonical. */
static inline bool is_canonical_address(xen_vaddr_t vaddr)
{
return ((int64_t)vaddr >> 47) == ((int64_t)vaddr >> 63);
}
/*
* Maps the guests shared info page.
*/
static int map_shinfo(struct xc_sr_context *ctx)
{
xc_interface *xch = ctx->xch;
ctx->x86.pv.shinfo = xc_map_foreign_range(
xch, ctx->domid, PAGE_SIZE, PROT_READ, ctx->dominfo.shared_info_frame);
if ( !ctx->x86.pv.shinfo )
{
PERROR("Failed to map shared info frame at mfn %#"PRIx64,
ctx->dominfo.shared_info_frame);
return -1;
}
return 0;
}
/*
* Copy a list of mfns from a guest, accounting for differences between guest
* and toolstack width. Can fail if truncation would occur.
*/
static int copy_mfns_from_guest(const struct xc_sr_context *ctx,
xen_pfn_t *dst, const void *src, size_t count)
{
size_t x;
if ( ctx->x86.pv.width == sizeof(unsigned long) )
memcpy(dst, src, count * sizeof(*dst));
else
{
for ( x = 0; x < count; ++x )
{
#ifdef __x86_64__
/* 64bit toolstack, 32bit guest. Expand any INVALID_MFN. */
uint32_t s = ((uint32_t *)src)[x];
dst[x] = s == ~0U ? INVALID_MFN : s;
#else
/*
* 32bit toolstack, 64bit guest. Truncate INVALID_MFN, but bail
* if any other truncation would occur.
*
* This will only occur on hosts where a PV guest has ram above
* the 16TB boundary. A 32bit dom0 is unlikely to have
* successfully booted on a system this large.
*/
uint64_t s = ((uint64_t *)src)[x];
if ( (s != ~0ULL) && ((s >> 32) != 0) )
{
errno = E2BIG;
return -1;
}
dst[x] = s;
#endif
}
}
return 0;
}
/*
* Map the p2m leave pages and build an array of their pfns.
*/
static int map_p2m_leaves(struct xc_sr_context *ctx, xen_pfn_t *mfns,
size_t n_mfns)
{
xc_interface *xch = ctx->xch;
unsigned int x;
ctx->x86.pv.p2m = xc_map_foreign_pages(xch, ctx->domid, PROT_READ,
mfns, n_mfns);
if ( !ctx->x86.pv.p2m )
{
PERROR("Failed to map p2m frames");
return -1;
}
ctx->save.p2m_size = ctx->x86.pv.max_pfn + 1;
ctx->x86.pv.p2m_frames = n_mfns;
ctx->x86.pv.p2m_pfns = malloc(n_mfns * sizeof(*mfns));
if ( !ctx->x86.pv.p2m_pfns )
{
ERROR("Cannot allocate %zu bytes for p2m pfns list",
n_mfns * sizeof(*mfns));
return -1;
}
/* Convert leaf frames from mfns to pfns. */
for ( x = 0; x < n_mfns; ++x )
{
if ( !mfn_in_pseudophysmap(ctx, mfns[x]) )
{
ERROR("Bad mfn in p2m_frame_list[%u]", x);
dump_bad_pseudophysmap_entry(ctx, mfns[x]);
errno = ERANGE;
return -1;
}
ctx->x86.pv.p2m_pfns[x] = mfn_to_pfn(ctx, mfns[x]);
}
return 0;
}
/*
* Walk the guests frame list list and frame list to identify and map the
* frames making up the guests p2m table. Construct a list of pfns making up
* the table.
*/
static int map_p2m_tree(struct xc_sr_context *ctx)
{
/* Terminology:
*
* fll - frame list list, top level p2m, list of fl mfns
* fl - frame list, mid level p2m, list of leaf mfns
* local - own allocated buffers, adjusted for bitness
* guest - mappings into the domain
*/
xc_interface *xch = ctx->xch;
int rc = -1;
unsigned int x, saved_x, fpp, fll_entries, fl_entries;
xen_pfn_t fll_mfn, saved_mfn, max_pfn;
xen_pfn_t *local_fll = NULL;
void *guest_fll = NULL;
size_t local_fll_size;
xen_pfn_t *local_fl = NULL;
void *guest_fl = NULL;
size_t local_fl_size;
fpp = PAGE_SIZE / ctx->x86.pv.width;
fll_entries = (ctx->x86.pv.max_pfn / (fpp * fpp)) + 1;
if ( fll_entries > fpp )
{
ERROR("max_pfn %#lx too large for p2m tree", ctx->x86.pv.max_pfn);
goto err;
}
fll_mfn = GET_FIELD(ctx->x86.pv.shinfo, arch.pfn_to_mfn_frame_list_list,
ctx->x86.pv.width);
if ( fll_mfn == 0 || fll_mfn > ctx->x86.pv.max_mfn )
{
ERROR("Bad mfn %#lx for p2m frame list list", fll_mfn);
goto err;
}
/* Map the guest top p2m. */
guest_fll = xc_map_foreign_range(xch, ctx->domid, PAGE_SIZE,
PROT_READ, fll_mfn);
if ( !guest_fll )
{
PERROR("Failed to map p2m frame list list at %#lx", fll_mfn);
goto err;
}
local_fll_size = fll_entries * sizeof(*local_fll);
local_fll = malloc(local_fll_size);
if ( !local_fll )
{
ERROR("Cannot allocate %zu bytes for local p2m frame list list",
local_fll_size);
goto err;
}
if ( copy_mfns_from_guest(ctx, local_fll, guest_fll, fll_entries) )
{
ERROR("Truncation detected copying p2m frame list list");
goto err;
}
/* Check for bad mfns in frame list list. */
saved_mfn = 0;
saved_x = 0;
for ( x = 0; x < fll_entries; ++x )
{
if ( local_fll[x] == 0 || local_fll[x] > ctx->x86.pv.max_mfn )
{
ERROR("Bad mfn %#lx at index %u (of %u) in p2m frame list list",
local_fll[x], x, fll_entries);
goto err;
}
if ( local_fll[x] != saved_mfn )
{
saved_mfn = local_fll[x];
saved_x = x;
}
}
/*
* Check for actual lower max_pfn:
* If the trailing entries of the frame list list were all the same we can
* assume they all reference mid pages all referencing p2m pages with all
* invalid entries. Otherwise there would be multiple pfns referencing all
* the same mfn which can't work across migration, as this sharing would be
* broken by the migration process.
* Adjust max_pfn if possible to avoid allocating much larger areas as
* needed for p2m and logdirty map.
*/
max_pfn = (saved_x + 1) * fpp * fpp - 1;
if ( max_pfn < ctx->x86.pv.max_pfn )
{
ctx->x86.pv.max_pfn = max_pfn;
fll_entries = (ctx->x86.pv.max_pfn / (fpp * fpp)) + 1;
}
ctx->x86.pv.p2m_frames = (ctx->x86.pv.max_pfn + fpp) / fpp;
DPRINTF("max_pfn %#lx, p2m_frames %d", ctx->x86.pv.max_pfn,
ctx->x86.pv.p2m_frames);
fl_entries = (ctx->x86.pv.max_pfn / fpp) + 1;
/* Map the guest mid p2m frames. */
guest_fl = xc_map_foreign_pages(xch, ctx->domid, PROT_READ,
local_fll, fll_entries);
if ( !guest_fl )
{
PERROR("Failed to map p2m frame list");
goto err;
}
local_fl_size = fl_entries * sizeof(*local_fl);
local_fl = malloc(local_fl_size);
if ( !local_fl )
{
ERROR("Cannot allocate %zu bytes for local p2m frame list",
local_fl_size);
goto err;
}
if ( copy_mfns_from_guest(ctx, local_fl, guest_fl, fl_entries) )
{
ERROR("Truncation detected copying p2m frame list");
goto err;
}
for ( x = 0; x < fl_entries; ++x )
{
if ( local_fl[x] == 0 || local_fl[x] > ctx->x86.pv.max_mfn )
{
ERROR("Bad mfn %#lx at index %u (of %u) in p2m frame list",
local_fl[x], x, fl_entries);
goto err;
}
}
/* Map the p2m leaves themselves. */
rc = map_p2m_leaves(ctx, local_fl, fl_entries);
err:
free(local_fl);
if ( guest_fl )
munmap(guest_fl, fll_entries * PAGE_SIZE);
free(local_fll);
if ( guest_fll )
munmap(guest_fll, PAGE_SIZE);
return rc;
}
/*
* Get p2m_generation count.
* Returns an error if the generation count has changed since the last call.
*/
static int get_p2m_generation(struct xc_sr_context *ctx)
{
uint64_t p2m_generation;
int rc;
p2m_generation = GET_FIELD(ctx->x86.pv.shinfo, arch.p2m_generation,
ctx->x86.pv.width);
rc = (p2m_generation == ctx->x86.pv.p2m_generation) ? 0 : -1;
ctx->x86.pv.p2m_generation = p2m_generation;
return rc;
}
static int x86_pv_check_vm_state_p2m_list(struct xc_sr_context *ctx)
{
xc_interface *xch = ctx->xch;
int rc;
if ( !ctx->save.live )
return 0;
rc = get_p2m_generation(ctx);
if ( rc )
ERROR("p2m generation count changed. Migration aborted.");
return rc;
}
/*
* Map the guest p2m frames specified via a cr3 value, a virtual address, and
* the maximum pfn. PTE entries are 64 bits for both, 32 and 64 bit guests as
* in 32 bit case we support PAE guests only.
*/
static int map_p2m_list(struct xc_sr_context *ctx, uint64_t p2m_cr3)
{
xc_interface *xch = ctx->xch;
xen_vaddr_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, shift, idx_start, idx_end, idx, saved_idx;
int rc = -1;
p2m_mfn = cr3_to_mfn(ctx, p2m_cr3);
assert(p2m_mfn != 0);
if ( p2m_mfn > ctx->x86.pv.max_mfn )
{
ERROR("Bad p2m_cr3 value %#" PRIx64, p2m_cr3);
errno = ERANGE;
goto err;
}
get_p2m_generation(ctx);
p2m_vaddr = GET_FIELD(ctx->x86.pv.shinfo, arch.p2m_vaddr,
ctx->x86.pv.width);
fpp = PAGE_SIZE / ctx->x86.pv.width;
ctx->x86.pv.p2m_frames = ctx->x86.pv.max_pfn / fpp + 1;
p2m_end = p2m_vaddr + ctx->x86.pv.p2m_frames * PAGE_SIZE - 1;
if ( ctx->x86.pv.width == 8 )
{
mask = 0x0000ffffffffffffULL;
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 err;
}
}
else
{
mask = 0x00000000ffffffffULL;
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 err;
}
}
DPRINTF("p2m list from %#" PRIx64 " to %#" PRIx64 ", root at %#lx",
p2m_vaddr, p2m_end, p2m_mfn);
DPRINTF("max_pfn %#lx, p2m_frames %d", ctx->x86.pv.max_pfn,
ctx->x86.pv.p2m_frames);
mfns = malloc(sizeof(*mfns));
if ( !mfns )
{
ERROR("Cannot allocate memory for array of %u mfns", 1);
goto err;
}
mfns[0] = p2m_mfn;
off = 0;
saved_mfn = 0;
idx_start = idx_end = saved_idx = 0;
for ( level = ctx->x86.pv.levels; level > 0; level-- )
{
n_pages = idx_end - idx_start + 1;
ptes = xc_map_foreign_pages(xch, ctx->domid, PROT_READ, mfns, n_pages);
if ( !ptes )
{
PERROR("Failed to map %u page table pages for p2m list", n_pages);
goto err;
}
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 err;
}
for ( idx = idx_start; idx <= idx_end; idx++ )
{
mfn = pte_to_frame(ptes[idx]);
if ( mfn == 0 || mfn > ctx->x86.pv.max_mfn )
{
ERROR("Bad mfn %#lx during page table walk for vaddr %#" PRIx64 " at level %d of p2m list",
mfn, off + ((xen_vaddr_t)idx << shift), level);
errno = ERANGE;
goto err;
}
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 - 1;
if ( max_pfn < ctx->x86.pv.max_pfn )
{
ctx->x86.pv.max_pfn = max_pfn;
ctx->x86.pv.p2m_frames = (ctx->x86.pv.max_pfn + fpp) / fpp;
p2m_end = p2m_vaddr + ctx->x86.pv.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);
}
/* Map the p2m leaves themselves. */
rc = map_p2m_leaves(ctx, mfns, idx_end - idx_start + 1);
err:
free(mfns);
if ( ptes )
munmap(ptes, n_pages * PAGE_SIZE);
return rc;
}
/*
* Map the guest p2m frames.
* Depending on guest support this might either be a virtual mapped linear
* list (preferred format) or a 3 level tree linked via mfns.
*/
static int map_p2m(struct xc_sr_context *ctx)
{
uint64_t p2m_cr3;
ctx->x86.pv.p2m_generation = ~0ULL;
ctx->x86.pv.max_pfn = GET_FIELD(ctx->x86.pv.shinfo, arch.max_pfn,
ctx->x86.pv.width) - 1;
p2m_cr3 = GET_FIELD(ctx->x86.pv.shinfo, arch.p2m_cr3, ctx->x86.pv.width);
return p2m_cr3 ? map_p2m_list(ctx, p2m_cr3) : map_p2m_tree(ctx);
}
/*
* Obtain a specific vcpus basic state and write an X86_PV_VCPU_BASIC record
* into the stream. Performs mfn->pfn conversion on architectural state.
*/
static int write_one_vcpu_basic(struct xc_sr_context *ctx, uint32_t id)
{
xc_interface *xch = ctx->xch;
xen_pfn_t mfn, pfn;
unsigned int i, gdt_count;
int rc = -1;
vcpu_guest_context_any_t vcpu;
struct xc_sr_rec_x86_pv_vcpu_hdr vhdr = {
.vcpu_id = id,
};
struct xc_sr_record rec = {
.type = REC_TYPE_X86_PV_VCPU_BASIC,
.length = sizeof(vhdr),
.data = &vhdr,
};
if ( xc_vcpu_getcontext(xch, ctx->domid, id, &vcpu) )
{
PERROR("Failed to get vcpu%u context", id);
goto err;
}
/* Vcpu0 is special: Convert the suspend record to a pfn. */
if ( id == 0 )
{
mfn = GET_FIELD(&vcpu, user_regs.edx, ctx->x86.pv.width);
if ( !mfn_in_pseudophysmap(ctx, mfn) )
{
ERROR("Bad mfn for suspend record");
dump_bad_pseudophysmap_entry(ctx, mfn);
errno = ERANGE;
goto err;
}
SET_FIELD(&vcpu, user_regs.edx, mfn_to_pfn(ctx, mfn),
ctx->x86.pv.width);
}
gdt_count = GET_FIELD(&vcpu, gdt_ents, ctx->x86.pv.width);
if ( gdt_count > FIRST_RESERVED_GDT_ENTRY )
{
ERROR("GDT entry count (%u) out of range (max %u)",
gdt_count, FIRST_RESERVED_GDT_ENTRY);
errno = ERANGE;
goto err;
}
gdt_count = (gdt_count + 511) / 512; /* gdt_count now in units of frames. */
/* Convert GDT frames to pfns. */
for ( i = 0; i < gdt_count; ++i )
{
mfn = GET_FIELD(&vcpu, gdt_frames[i], ctx->x86.pv.width);
if ( !mfn_in_pseudophysmap(ctx, mfn) )
{
ERROR("Bad mfn for frame %u of vcpu%u's GDT", i, id);
dump_bad_pseudophysmap_entry(ctx, mfn);
errno = ERANGE;
goto err;
}
SET_FIELD(&vcpu, gdt_frames[i], mfn_to_pfn(ctx, mfn),
ctx->x86.pv.width);
}
/* Convert CR3 to a pfn. */
mfn = cr3_to_mfn(ctx, GET_FIELD(&vcpu, ctrlreg[3], ctx->x86.pv.width));
if ( !mfn_in_pseudophysmap(ctx, mfn) )
{
ERROR("Bad mfn for vcpu%u's cr3", id);
dump_bad_pseudophysmap_entry(ctx, mfn);
errno = ERANGE;
goto err;
}
pfn = mfn_to_pfn(ctx, mfn);
SET_FIELD(&vcpu, ctrlreg[3], mfn_to_cr3(ctx, pfn), ctx->x86.pv.width);
/* 64bit guests: Convert CR1 (guest pagetables) to pfn. */
if ( ctx->x86.pv.levels == 4 && vcpu.x64.ctrlreg[1] )
{
mfn = vcpu.x64.ctrlreg[1] >> PAGE_SHIFT;
if ( !mfn_in_pseudophysmap(ctx, mfn) )
{
ERROR("Bad mfn for vcpu%u's cr1", id);
dump_bad_pseudophysmap_entry(ctx, mfn);
errno = ERANGE;
goto err;
}
pfn = mfn_to_pfn(ctx, mfn);
vcpu.x64.ctrlreg[1] = 1 | ((uint64_t)pfn << PAGE_SHIFT);
}
if ( ctx->x86.pv.width == 8 )
rc = write_split_record(ctx, &rec, &vcpu, sizeof(vcpu.x64));
else
rc = write_split_record(ctx, &rec, &vcpu, sizeof(vcpu.x32));
err:
return rc;
}
/*
* Obtain a specific vcpus extended state and write an X86_PV_VCPU_EXTENDED
* record into the stream.
*/
static int write_one_vcpu_extended(struct xc_sr_context *ctx, uint32_t id)
{
xc_interface *xch = ctx->xch;
struct xc_sr_rec_x86_pv_vcpu_hdr vhdr = {
.vcpu_id = id,
};
struct xc_sr_record rec = {
.type = REC_TYPE_X86_PV_VCPU_EXTENDED,
.length = sizeof(vhdr),
.data = &vhdr,
};
struct xen_domctl domctl = {
.cmd = XEN_DOMCTL_get_ext_vcpucontext,
.domain = ctx->domid,
.u.ext_vcpucontext.vcpu = id,
};
if ( xc_domctl(xch, &domctl) < 0 )
{
PERROR("Unable to get vcpu%u extended context", id);
return -1;
}
/* No content? Skip the record. */
if ( domctl.u.ext_vcpucontext.size == 0 )
return 0;
return write_split_record(ctx, &rec, &domctl.u.ext_vcpucontext,
domctl.u.ext_vcpucontext.size);
}
/*
* Query to see whether a specific vcpu has xsave state and if so, write an
* X86_PV_VCPU_XSAVE record into the stream.
*/
static int write_one_vcpu_xsave(struct xc_sr_context *ctx, uint32_t id)
{
xc_interface *xch = ctx->xch;
int rc = -1;
DECLARE_HYPERCALL_BUFFER(void, buffer);
struct xc_sr_rec_x86_pv_vcpu_hdr vhdr = {
.vcpu_id = id,
};
struct xc_sr_record rec = {
.type = REC_TYPE_X86_PV_VCPU_XSAVE,
.length = sizeof(vhdr),
.data = &vhdr,
};
struct xen_domctl domctl = {
.cmd = XEN_DOMCTL_getvcpuextstate,
.domain = ctx->domid,
.u.vcpuextstate.vcpu = id,
};
if ( xc_domctl(xch, &domctl) < 0 )
{
PERROR("Unable to get vcpu%u's xsave context", id);
goto err;
}
/* No xsave state? skip this record. */
if ( !domctl.u.vcpuextstate.xfeature_mask )
goto out;
buffer = xc_hypercall_buffer_alloc(xch, buffer, domctl.u.vcpuextstate.size);
if ( !buffer )
{
ERROR("Unable to allocate %"PRIx64" bytes for vcpu%u's xsave context",
domctl.u.vcpuextstate.size, id);
goto err;
}
set_xen_guest_handle(domctl.u.vcpuextstate.buffer, buffer);
if ( xc_domctl(xch, &domctl) < 0 )
{
PERROR("Unable to get vcpu%u's xsave context", id);
goto err;
}
/* No xsave state? Skip this record. */
if ( domctl.u.vcpuextstate.size == 0 )
goto out;
rc = write_split_record(ctx, &rec, buffer, domctl.u.vcpuextstate.size);
if ( rc )
goto err;
out:
rc = 0;
err:
xc_hypercall_buffer_free(xch, buffer);
return rc;
}
/*
* Query to see whether a specific vcpu has msr state and if so, write an
* X86_PV_VCPU_MSRS record into the stream.
*/
static int write_one_vcpu_msrs(struct xc_sr_context *ctx, uint32_t id)
{
xc_interface *xch = ctx->xch;
int rc = -1;
size_t buffersz;
DECLARE_HYPERCALL_BUFFER(void, buffer);
struct xc_sr_rec_x86_pv_vcpu_hdr vhdr = {
.vcpu_id = id,
};
struct xc_sr_record rec = {
.type = REC_TYPE_X86_PV_VCPU_MSRS,
.length = sizeof(vhdr),
.data = &vhdr,
};
struct xen_domctl domctl = {
.cmd = XEN_DOMCTL_get_vcpu_msrs,
.domain = ctx->domid,
.u.vcpu_msrs.vcpu = id,
};
if ( xc_domctl(xch, &domctl) < 0 )
{
PERROR("Unable to get vcpu%u's msrs", id);
goto err;
}
/* No MSRs? skip this record. */
if ( !domctl.u.vcpu_msrs.msr_count )
goto out;
buffersz = domctl.u.vcpu_msrs.msr_count * sizeof(xen_domctl_vcpu_msr_t);
buffer = xc_hypercall_buffer_alloc(xch, buffer, buffersz);
if ( !buffer )
{
ERROR("Unable to allocate %zu bytes for vcpu%u's msrs",
buffersz, id);
goto err;
}
set_xen_guest_handle(domctl.u.vcpu_msrs.msrs, buffer);
if ( xc_domctl(xch, &domctl) < 0 )
{
PERROR("Unable to get vcpu%u's msrs", id);
goto err;
}
/* No MSRs? Skip this record. */
if ( domctl.u.vcpu_msrs.msr_count == 0 )
goto out;
rc = write_split_record(ctx, &rec, buffer,
domctl.u.vcpu_msrs.msr_count *
sizeof(xen_domctl_vcpu_msr_t));
if ( rc )
goto err;
out:
rc = 0;
err:
xc_hypercall_buffer_free(xch, buffer);
return rc;
}
/*
* For each vcpu, if it is online, write its state into the stream.
*/
static int write_all_vcpu_information(struct xc_sr_context *ctx)
{
xc_interface *xch = ctx->xch;
xc_vcpuinfo_t vinfo;
unsigned int i;
int rc;
for ( i = 0; i <= ctx->dominfo.max_vcpu_id; ++i )
{
rc = xc_vcpu_getinfo(xch, ctx->domid, i, &vinfo);
if ( rc )
{
PERROR("Failed to get vcpu%u information", i);
return rc;
}
/* Vcpu offline? skip all these records. */
if ( !vinfo.online )
continue;
rc = write_one_vcpu_basic(ctx, i);
if ( rc )
return rc;
rc = write_one_vcpu_extended(ctx, i);
if ( rc )
return rc;
rc = write_one_vcpu_xsave(ctx, i);
if ( rc )
return rc;
rc = write_one_vcpu_msrs(ctx, i);
if ( rc )
return rc;
}
return 0;
}
/*
* Writes an X86_PV_INFO record into the stream.
*/
static int write_x86_pv_info(struct xc_sr_context *ctx)
{
struct xc_sr_rec_x86_pv_info info = {
.guest_width = ctx->x86.pv.width,
.pt_levels = ctx->x86.pv.levels,
};
struct xc_sr_record rec = {
.type = REC_TYPE_X86_PV_INFO,
.length = sizeof(info),
.data = &info,
};
return write_record(ctx, &rec);
}
/*
* Writes an X86_PV_P2M_FRAMES record into the stream. This contains the list
* of pfns making up the p2m table.
*/
static int write_x86_pv_p2m_frames(struct xc_sr_context *ctx)
{
xc_interface *xch = ctx->xch;
int rc; unsigned int i;
size_t datasz = ctx->x86.pv.p2m_frames * sizeof(uint64_t);
uint64_t *data = NULL;
struct xc_sr_rec_x86_pv_p2m_frames hdr = {
.end_pfn = ctx->x86.pv.max_pfn,
};
struct xc_sr_record rec = {
.type = REC_TYPE_X86_PV_P2M_FRAMES,
.length = sizeof(hdr),
.data = &hdr,
};
/* No need to translate if sizeof(uint64_t) == sizeof(xen_pfn_t). */
if ( sizeof(uint64_t) != sizeof(*ctx->x86.pv.p2m_pfns) )
{
if ( !(data = malloc(datasz)) )
{
ERROR("Cannot allocate %zu bytes for X86_PV_P2M_FRAMES data",
datasz);
return -1;
}
for ( i = 0; i < ctx->x86.pv.p2m_frames; ++i )
data[i] = ctx->x86.pv.p2m_pfns[i];
}
else
data = (uint64_t *)ctx->x86.pv.p2m_pfns;
rc = write_split_record(ctx, &rec, data, datasz);
if ( data != (uint64_t *)ctx->x86.pv.p2m_pfns )
free(data);
return rc;
}
/*
* Writes an SHARED_INFO record into the stream.
*/
static int write_shared_info(struct xc_sr_context *ctx)
{
struct xc_sr_record rec = {
.type = REC_TYPE_SHARED_INFO,
.length = PAGE_SIZE,
.data = ctx->x86.pv.shinfo,
};
return write_record(ctx, &rec);
}
/*
* Normalise a pagetable for the migration stream. Performs mfn->pfn
* conversions on the ptes.
*/
static int normalise_pagetable(struct xc_sr_context *ctx, const uint64_t *src,
uint64_t *dst, unsigned long type)
{
xc_interface *xch = ctx->xch;
uint64_t pte;
unsigned int i, xen_first = -1, xen_last = -1; /* Indices of Xen mappings. */
type &= XEN_DOMCTL_PFINFO_LTABTYPE_MASK;
if ( ctx->x86.pv.levels == 4 )
{
/* 64bit guests only have Xen mappings in their L4 tables. */
if ( type == XEN_DOMCTL_PFINFO_L4TAB )
{
xen_first = (HYPERVISOR_VIRT_START_X86_64 >>
L4_PAGETABLE_SHIFT_X86_64) & 511;
xen_last = (HYPERVISOR_VIRT_END_X86_64 >>
L4_PAGETABLE_SHIFT_X86_64) & 511;
}
}
else
{
switch ( type )
{
case XEN_DOMCTL_PFINFO_L4TAB:
ERROR("??? Found L4 table for 32bit guest");
errno = EINVAL;
return -1;
case XEN_DOMCTL_PFINFO_L3TAB:
/* 32bit guests can only use the first 4 entries of their L3 tables.
* All other are potentially used by Xen. */
xen_first = 4;
xen_last = 511;
break;
case XEN_DOMCTL_PFINFO_L2TAB:
/* It is hard to spot Xen mappings in a 32bit guest's L2. Most
* are normal but only a few will have Xen mappings.
*/
i = (HYPERVISOR_VIRT_START_X86_32 >> L2_PAGETABLE_SHIFT_PAE) & 511;
if ( pte_to_frame(src[i]) == ctx->x86.pv.compat_m2p_mfn0 )
{
xen_first = i;
xen_last = (HYPERVISOR_VIRT_END_X86_32 >>
L2_PAGETABLE_SHIFT_PAE) & 511;
}
break;
}
}
for ( i = 0; i < (PAGE_SIZE / sizeof(uint64_t)); ++i )
{
xen_pfn_t mfn;
pte = src[i];
/* Remove Xen mappings: Xen will reconstruct on the other side. */
if ( i >= xen_first && i <= xen_last )
pte = 0;
/*
* Errors during the live part of migration are expected as a result
* of split pagetable updates, page type changes, active grant
* mappings etc. The pagetable will need to be resent after pausing.
* In such cases we fail with EAGAIN.
*
* For domains which are already paused, errors are fatal.
*/
if ( pte & _PAGE_PRESENT )
{
mfn = pte_to_frame(pte);
#ifdef __i386__
if ( mfn == INVALID_MFN )
{
if ( !(ctx->dominfo.flags & XEN_DOMINF_paused) )
errno = EAGAIN;
else
{
ERROR("PTE truncation detected. L%lu[%u] = %016"PRIx64,
type >> XEN_DOMCTL_PFINFO_LTAB_SHIFT, i, pte);
errno = E2BIG;
}
return -1;
}
#endif
if ( (type > XEN_DOMCTL_PFINFO_L1TAB) && (pte & _PAGE_PSE) )
{
ERROR("Cannot migrate superpage (L%lu[%u]: 0x%016"PRIx64")",
type >> XEN_DOMCTL_PFINFO_LTAB_SHIFT, i, pte);
errno = E2BIG;
return -1;
}
if ( !mfn_in_pseudophysmap(ctx, mfn) )
{
if ( !(ctx->dominfo.flags & XEN_DOMINF_paused) )
errno = EAGAIN;
else
{
ERROR("Bad mfn for L%lu[%u]",
type >> XEN_DOMCTL_PFINFO_LTAB_SHIFT, i);
dump_bad_pseudophysmap_entry(ctx, mfn);
errno = ERANGE;
}
return -1;
}
pte = merge_pte(pte, mfn_to_pfn(ctx, mfn));
}
dst[i] = pte;
}
return 0;
}
static xen_pfn_t x86_pv_pfn_to_gfn(const struct xc_sr_context *ctx,
xen_pfn_t pfn)
{
assert(pfn <= ctx->x86.pv.max_pfn);
return xc_pfn_to_mfn(pfn, ctx->x86.pv.p2m, ctx->x86.pv.width);
}
/*
* save_ops function. Performs pagetable normalisation on appropriate pages.
*/
static int x86_pv_normalise_page(struct xc_sr_context *ctx, xen_pfn_t type,
void **page)
{
xc_interface *xch = ctx->xch;
void *local_page;
int rc;
type &= XEN_DOMCTL_PFINFO_LTABTYPE_MASK;
if ( type < XEN_DOMCTL_PFINFO_L1TAB || type > XEN_DOMCTL_PFINFO_L4TAB )
return 0;
local_page = malloc(PAGE_SIZE);
if ( !local_page )
{
ERROR("Unable to allocate scratch page");
rc = -1;
goto out;
}
rc = normalise_pagetable(ctx, *page, local_page, type);
*page = local_page;
out:
return rc;
}
/*
* save_ops function. Queries domain information and maps the Xen m2p and the
* guests shinfo and p2m table.
*/
static int x86_pv_setup(struct xc_sr_context *ctx)
{
int rc;
rc = x86_pv_domain_info(ctx);
if ( rc )
return rc;
rc = x86_pv_map_m2p(ctx);
if ( rc )
return rc;
rc = map_shinfo(ctx);
if ( rc )
return rc;
rc = map_p2m(ctx);
if ( rc )
return rc;
return 0;
}
static int x86_pv_static_data(struct xc_sr_context *ctx)
{
int rc;
rc = write_x86_pv_info(ctx);
if ( rc )
return rc;
rc = write_x86_cpu_policy_records(ctx);
if ( rc )
return rc;
return 0;
}
static int x86_pv_start_of_stream(struct xc_sr_context *ctx)
{
int rc;
/*
* Ideally should be able to change during migration. Currently
* corruption will occur if the contents or location of the P2M changes
* during the live migration loop. If one is very lucky, the breakage
* will not be subtle.
*/
rc = write_x86_pv_p2m_frames(ctx);
if ( rc )
return rc;
return 0;
}
static int x86_pv_start_of_checkpoint(struct xc_sr_context *ctx)
{
return 0;
}
static int x86_pv_end_of_checkpoint(struct xc_sr_context *ctx)
{
int rc;
rc = write_x86_tsc_info(ctx);
if ( rc )
return rc;
rc = write_shared_info(ctx);
if ( rc )
return rc;
rc = write_all_vcpu_information(ctx);
if ( rc )
return rc;
return 0;
}
static int x86_pv_check_vm_state(struct xc_sr_context *ctx)
{
if ( ctx->x86.pv.p2m_generation == ~0ULL )
return 0;
return x86_pv_check_vm_state_p2m_list(ctx);
}
static int x86_pv_cleanup(struct xc_sr_context *ctx)
{
free(ctx->x86.pv.p2m_pfns);
if ( ctx->x86.pv.p2m )
munmap(ctx->x86.pv.p2m, ctx->x86.pv.p2m_frames * PAGE_SIZE);
if ( ctx->x86.pv.shinfo )
munmap(ctx->x86.pv.shinfo, PAGE_SIZE);
if ( ctx->x86.pv.m2p )
munmap(ctx->x86.pv.m2p, ctx->x86.pv.nr_m2p_frames * PAGE_SIZE);
return 0;
}
struct xc_sr_save_ops save_ops_x86_pv =
{
.pfn_to_gfn = x86_pv_pfn_to_gfn,
.normalise_page = x86_pv_normalise_page,
.setup = x86_pv_setup,
.static_data = x86_pv_static_data,
.start_of_stream = x86_pv_start_of_stream,
.start_of_checkpoint = x86_pv_start_of_checkpoint,
.end_of_checkpoint = x86_pv_end_of_checkpoint,
.check_vm_state = x86_pv_check_vm_state,
.cleanup = x86_pv_cleanup,
};
/*
* Local variables:
* mode: C
* c-file-style: "BSD"
* c-basic-offset: 4
* tab-width: 4
* indent-tabs-mode: nil
* End:
*/
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