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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v10 08/15] tools/libxc: x86 PV save code
Save the x86 PV specific parts of a domain. This is the X86_PV_INFO record,
the P2M_FRAMES, the X86_PV_SHARED_INFO, the three different VCPU context
records, and the MSR records.
The normalise_page callback used by the common code when writing the PAGE_DATA
records, converts MFNs in page tables to PFNs.
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Acked-by: Ian Campbell <Ian.Campbell@xxxxxxxxxx>
CC: Ian Jackson <Ian.Jackson@xxxxxxxxxxxxx>
CC: Wei Liu <wei.liu2@xxxxxxxxxx>
---
v10: Bail with a hard error if pfn truncation would occur
---
tools/libxc/Makefile | 1 +
tools/libxc/xc_sr_common.h | 1 +
tools/libxc/xc_sr_save_x86_pv.c | 885 +++++++++++++++++++++++++++++++++++++++
3 files changed, 887 insertions(+)
create mode 100644 tools/libxc/xc_sr_save_x86_pv.c
diff --git a/tools/libxc/Makefile b/tools/libxc/Makefile
index c2e62a8..40ba91c 100644
--- a/tools/libxc/Makefile
+++ b/tools/libxc/Makefile
@@ -57,6 +57,7 @@ GUEST_SRCS-y += xc_domain_restore.c xc_domain_save.c
GUEST_SRCS-y += xc_sr_common.c
GUEST_SRCS-$(CONFIG_X86) += xc_sr_common_x86.c
GUEST_SRCS-$(CONFIG_X86) += xc_sr_common_x86_pv.c
+GUEST_SRCS-$(CONFIG_X86) += xc_sr_save_x86_pv.c
GUEST_SRCS-y += xc_sr_restore.c
GUEST_SRCS-y += xc_sr_save.c
GUEST_SRCS-y += xc_offline_page.c xc_compression.c
diff --git a/tools/libxc/xc_sr_common.h b/tools/libxc/xc_sr_common.h
index b71b532..2f0f00b 100644
--- a/tools/libxc/xc_sr_common.h
+++ b/tools/libxc/xc_sr_common.h
@@ -285,6 +285,7 @@ struct xc_sr_context
};
};
+extern struct xc_sr_save_ops save_ops_x86_pv;
struct xc_sr_record
{
diff --git a/tools/libxc/xc_sr_save_x86_pv.c b/tools/libxc/xc_sr_save_x86_pv.c
new file mode 100644
index 0000000..a668221
--- /dev/null
+++ b/tools/libxc/xc_sr_save_x86_pv.c
@@ -0,0 +1,885 @@
+#include <assert.h>
+#include <limits.h>
+
+#include "xc_sr_common_x86_pv.h"
+
+/*
+ * 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 %#lx",
+ 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;
+}
+
+/*
+ * 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(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 x, fpp, fll_entries, fl_entries;
+ xen_pfn_t fll_mfn;
+
+ 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;
+ fl_entries = (ctx->x86_pv.max_pfn / fpp) + 1;
+
+ 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. */
+ 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;
+ }
+ }
+
+ /* 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. */
+ ctx->x86_pv.p2m = xc_map_foreign_pages(xch, ctx->domid, PROT_READ,
+ local_fl, fl_entries);
+ if ( !ctx->x86_pv.p2m )
+ {
+ PERROR("Failed to map p2m frames");
+ goto err;
+ }
+
+ ctx->x86_pv.p2m_frames = fl_entries;
+ ctx->x86_pv.p2m_pfns = malloc(local_fl_size);
+ if ( !ctx->x86_pv.p2m_pfns )
+ {
+ ERROR("Cannot allocate %zu bytes for p2m pfns list",
+ local_fl_size);
+ goto err;
+ }
+
+ /* Convert leaf frames from mfns to pfns. */
+ for ( x = 0; x < fl_entries; ++x )
+ {
+ if ( !mfn_in_pseudophysmap(ctx, local_fl[x]) )
+ {
+ ERROR("Bad mfn in p2m_frame_list[%u]", x);
+ dump_bad_pseudophysmap_entry(ctx, local_fl[x]);
+ errno = ERANGE;
+ goto err;
+ }
+
+ ctx->x86_pv.p2m_pfns[x] = mfn_to_pfn(ctx, local_fl[x]);
+ }
+
+ rc = 0;
+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;
+}
+
+/*
+ * 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 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;
+ }
+
+ 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;
+ }
+
+ 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;
+ }
+
+ 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 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 =
+ {
+ .start_pfn = 0,
+ .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 pfn->mfn
+ * 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 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 = 256;
+ xen_last = 271;
+ }
+ }
+ 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 = 512;
+ 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.
+ *
+ * 428 = (HYPERVISOR_VIRT_START_PAE >>
L2_PAGETABLE_SHIFT_PAE)&0x1ff
+ *
+ * ...which is conveniently unavailable to us in a 64bit build.
+ */
+ if ( pte_to_frame(src[428]) == ctx->x86_pv.compat_m2p_mfn0 )
+ {
+ xen_first = 428;
+ xen_last = 512;
+ }
+ 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 )
+ {
+ 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) )
+ {
+ if ( !ctx->dominfo.paused )
+ errno = EAGAIN;
+ else
+ {
+ 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.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;
+}
+
+/* save_ops function. */
+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;
+}
+
+/*
+ * save_ops function. Writes PV header records into the stream.
+ */
+static int x86_pv_start_of_stream(struct xc_sr_context *ctx)
+{
+ int rc;
+
+ rc = write_x86_pv_info(ctx);
+ if ( rc )
+ return rc;
+
+ rc = write_x86_pv_p2m_frames(ctx);
+ if ( rc )
+ return rc;
+
+ return 0;
+}
+
+/*
+ * save_ops function. Writes tail records information into the stream.
+ */
+static int x86_pv_end_of_stream(struct xc_sr_context *ctx)
+{
+ int rc;
+
+ rc = write_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;
+}
+
+/*
+ * save_ops function. Cleanup.
+ */
+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,
+ .start_of_stream = x86_pv_start_of_stream,
+ .end_of_stream = x86_pv_end_of_stream,
+ .cleanup = x86_pv_cleanup,
+};
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
--
1.7.10.4
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