HVM save restore: guest memory handling

diff -r bb1c450b2739 tools/libxc/xc_hvm_restore.c
@@ -31,6 +31,40 @@
 #include <xen/hvm/ioreq.h>
 #include <xen/hvm/params.h>
 #include <xen/hvm/e820.h>
+
+/* max mfn of the whole machine */
+static unsigned long max_mfn;
+
+/* virtual starting address of the hypervisor */
+static unsigned long hvirt_start;
+
+/* #levels of page tables used by the currrent guest */
+static unsigned int pt_levels;
+
+/* total number of pages used by the current guest */
+static unsigned long max_pfn;
+
+/* A table mapping each PFN to its new MFN. */
+static xen_pfn_t *p2m = NULL;
+
+static ssize_t
+read_exact(int fd, void *buf, size_t count)
+{
+    int r = 0, s;
+    unsigned char *b = buf;
+
+    while (r < count) {
+        s = read(fd, &b[r], count - r);
+        if ((s == -1) && (errno == EINTR))
+            continue;
+        if (s <= 0) {
+            break;
+        }
+        r += s;
+    }
+
+    return (r == count) ? 1 : 0;
+}
 
 int xc_hvm_restore(int xc_handle, int io_fd,
                      uint32_t dom, unsigned long nr_pfns,

@@ -38,5 +72,289 @@ int xc_hvm_restore(int xc_handle, int io
                      unsigned int console_evtchn, unsigned long *console_mfn,
                      unsigned int pae, unsigned int apic)
 {
-    return 0;
+    DECLARE_DOMCTL;
+
+    /* The new domain's shared-info frame number. */
+    unsigned long shared_info_frame;
+
+    /* A copy of the CPU context of the guest. */
+    vcpu_guest_context_t ctxt;
+
+    char *region_base;
+
+    unsigned long buf[PAGE_SIZE/sizeof(unsigned long)];
+
+    xc_dominfo_t info;
+    unsigned int rc = 1, n, i;
+    uint32_t rec_len, nr_vcpus;
+    hvm_domain_context_t hvm_ctxt;
+    unsigned long long v_end, memsize;
+    unsigned long shared_page_nr;
+
+    unsigned long mfn, pfn;
+    unsigned int prev_pc, this_pc;
+    int verify = 0;
+
+    /* Types of the pfns in the current region */
+    unsigned long region_pfn_type[MAX_BATCH_SIZE];
+
+    /* hvm guest mem size (Mb) */
+    memsize = (unsigned long long)*store_mfn;
+    v_end = memsize << 20;
+
+    DPRINTF("xc_hvm_restore:dom=%d, nr_pfns=0x%lx, store_evtchn=%d, *store_mfn=%ld, console_evtchn=%d, *console_mfn=%ld, pae=%u, apic=%u.\n", 
+            dom, nr_pfns, store_evtchn, *store_mfn, console_evtchn, *console_mfn, pae, apic);
+
+    max_pfn = nr_pfns;
+
+    if(!get_platform_info(xc_handle, dom,
+                          &max_mfn, &hvirt_start, &pt_levels)) {
+        ERROR("Unable to get platform info.");
+        return 1;
+    }
+
+    DPRINTF("xc_hvm_restore start: max_pfn = %lx, max_mfn = %lx, hvirt_start=%lx, pt_levels=%d\n",
+            max_pfn,
+            max_mfn,
+            hvirt_start,
+            pt_levels);
+
+    if (mlock(&ctxt, sizeof(ctxt))) {
+        /* needed for build dom0 op, but might as well do early */
+        ERROR("Unable to mlock ctxt");
+        return 1;
+    }
+
+
+    p2m        = malloc(max_pfn * sizeof(xen_pfn_t));
+
+    if (p2m == NULL) {
+        ERROR("memory alloc failed");
+        errno = ENOMEM;
+        goto out;
+    }
+
+    /* Get the domain's shared-info frame. */
+    domctl.cmd = XEN_DOMCTL_getdomaininfo;
+    domctl.domain = (domid_t)dom;
+    if (xc_domctl(xc_handle, &domctl) < 0) {
+        ERROR("Could not get information on new domain");
+        goto out;
+    }
+    shared_info_frame = domctl.u.getdomaininfo.shared_info_frame;
+
+    if(xc_domain_setmaxmem(xc_handle, dom, PFN_TO_KB(max_pfn)) != 0) {
+        errno = ENOMEM;
+        goto out;
+    }
+
+    for ( i = 0; i < max_pfn; i++ )
+        p2m[i] = i;
+    for ( i = HVM_BELOW_4G_RAM_END >> PAGE_SHIFT; i < max_pfn; i++ )
+        p2m[i] += HVM_BELOW_4G_MMIO_LENGTH >> PAGE_SHIFT;
+
+    /* Allocate memory for HVM guest, skipping VGA hole 0xA0000-0xC0000. */
+    rc = xc_domain_memory_populate_physmap(
+        xc_handle, dom, (max_pfn > 0xa0) ? 0xa0 : max_pfn,
+        0, 0, &p2m[0x00]);
+    if ( (rc == 0) && (max_pfn > 0xc0) )
+        rc = xc_domain_memory_populate_physmap(
+            xc_handle, dom, max_pfn - 0xc0, 0, 0, &p2m[0xc0]);
+    if ( rc != 0 )
+    {
+        PERROR("Could not allocate memory for HVM guest.\n");
+        goto out;
+    }
+
+
+    /**********XXXXXXXXXXXXXXXX******************/
+    if (xc_domain_getinfo(xc_handle, dom, 1, &info) != 1) {
+        ERROR("Could not get domain info");
+        return 1;
+    }
+
+    domctl.cmd = XEN_DOMCTL_getdomaininfo;
+    domctl.domain = (domid_t)dom;
+    if (xc_domctl(xc_handle, &domctl) < 0) {
+        ERROR("Could not get information on new domain");
+        goto out;
+    }
+
+    for ( i = 0; i < max_pfn; i++)
+        p2m[i] = i;
+
+    prev_pc = 0;
+
+    n = 0;
+    while (1) {
+
+        int j;
+
+        this_pc = (n * 100) / max_pfn;
+        if ( (this_pc - prev_pc) >= 5 )
+        {
+            PPRINTF("\b\b\b\b%3d%%", this_pc);
+            prev_pc = this_pc;
+        }
+
+        if (!read_exact(io_fd, &j, sizeof(int))) {
+            ERROR("HVM restore Error when reading batch size");
+            goto out;
+        }
+
+        PPRINTF("batch %d\n",j);
+
+        if (j == -1) {
+            verify = 1;
+            DPRINTF("Entering page verify mode\n");
+            continue;
+        }
+
+        if (j == 0)
+            break;  /* our work here is done */
+
+        if (j > MAX_BATCH_SIZE) {
+            ERROR("Max batch size exceeded. Giving up.");
+            goto out;
+        }
+
+        if (!read_exact(io_fd, region_pfn_type, j*sizeof(unsigned long))) {
+            ERROR("Error when reading region pfn types");
+            goto out;
+        }
+
+        region_base = xc_map_foreign_batch(
+            xc_handle, dom, PROT_WRITE, region_pfn_type, j);
+
+        for ( i = 0; i < j; i++ )
+        {
+            void *page;
+
+            pfn = region_pfn_type[i];
+            if ( pfn > max_pfn )
+            {
+                ERROR("pfn out of range");
+                goto out;
+            }
+
+            if ( pfn >= 0xa0 && pfn < 0xc0) {
+                ERROR("hvm restore:pfn in vga hole");
+                goto out;
+            }
+
+
+            mfn = p2m[pfn];
+
+            /* In verify mode, we use a copy; otherwise we work in place */
+            page = verify ? (void *)buf : (region_base + i*PAGE_SIZE);
+
+            if (!read_exact(io_fd, page, PAGE_SIZE)) {
+                ERROR("Error when reading page (%x)", i);
+                goto out;
+            }
+
+            if (verify) {
+
+                int res = memcmp(buf, (region_base + i*PAGE_SIZE), PAGE_SIZE);
+
+                if (res) {
+
+                    int v;
+
+                    DPRINTF("************** pfn=%lx mfn=%lx gotcs=%08lx "
+                            "actualcs=%08lx\n", pfn, p2m[pfn],
+                            csum_page(region_base + i*PAGE_SIZE),
+                            csum_page(buf));
+
+                    for (v = 0; v < 4; v++) {
+
+                        unsigned long *p = (unsigned long *)
+                            (region_base + i*PAGE_SIZE);
+                        if (buf[v] != p[v])
+                            DPRINTF("    %d: %08lx %08lx\n", v, buf[v], p[v]);
+                    }
+                }
+            }
+
+        } /* end of 'batch' for loop */
+        munmap(region_base, j*PAGE_SIZE);
+        n+= j; /* crude stats */
+
+    }/*while 1*/
+    
+/*    xc_set_hvm_param(xc_handle, dom, HVM_PARAM_APIC_ENABLED, apic);*/
+    xc_set_hvm_param(xc_handle, dom, HVM_PARAM_PAE_ENABLED, pae);
+    xc_set_hvm_param(xc_handle, dom, HVM_PARAM_STORE_EVTCHN, store_evtchn);
+
+    if ( v_end > HVM_BELOW_4G_RAM_END )
+        shared_page_nr = (HVM_BELOW_4G_RAM_END >> PAGE_SHIFT) - 1;
+    else
+        shared_page_nr = (v_end >> PAGE_SHIFT) - 1;
+
+    xc_set_hvm_param(xc_handle, dom, HVM_PARAM_STORE_PFN, shared_page_nr-1);
+    xc_set_hvm_param(xc_handle, dom, HVM_PARAM_BUFIOREQ_PFN, shared_page_nr-2);
+    xc_set_hvm_param(xc_handle, dom, HVM_PARAM_IOREQ_PFN, shared_page_nr);
+
+    /* caculate the store_mfn , wrong val cause hang when introduceDomain */
+    *store_mfn = (v_end >> PAGE_SHIFT) - 2;
+    DPRINTF("hvm restore:calculate new store_mfn=0x%lx,v_end=0x%llx..\n", *store_mfn, v_end);
+
+    /* restore hvm context including pic/pit/shpage */
+    if (!read_exact(io_fd, &rec_len, sizeof(uint32_t))) {
+        ERROR("error read hvm context size!\n");
+        goto out;
+    }
+    if (rec_len != sizeof(hvm_ctxt)) {
+        ERROR("hvm context size dismatch!\n");
+        goto out;
+    }
+
+    if (!read_exact(io_fd, &hvm_ctxt, sizeof(hvm_ctxt))) {
+        ERROR("error read hvm context!\n");
+        goto out;
+    }
+
+    if (( rc = xc_domain_hvm_setcontext(xc_handle, dom, &hvm_ctxt))) {
+        ERROR("error set hvm context!\n");
+        goto out;
+    }
+
+    if (!read_exact(io_fd, &nr_vcpus, sizeof(uint32_t))) {
+        ERROR("error read nr vcpu !\n");
+        goto out;
+    }
+    DPRINTF("hvm restore:get nr_vcpus=%d.\n", nr_vcpus);
+
+    for (i =0; i < nr_vcpus; i++) {
+        if (!read_exact(io_fd, &rec_len, sizeof(uint32_t))) {
+            ERROR("error read vcpu context size!\n");
+            goto out;
+        }
+        if (rec_len != sizeof(ctxt)) {
+            ERROR("vcpu context size dismatch!\n");
+            goto out;
+        }
+
+        if (!read_exact(io_fd, &(ctxt), sizeof(ctxt))) {
+            ERROR("error read vcpu context.\n");
+            goto out;
+        }
+
+        if ( (rc = xc_vcpu_setcontext(xc_handle, dom, i, &ctxt)) ) {
+            ERROR("Could not set vcpu context, rc=%d", rc);
+            goto out;
+        }
+    }
+
+    rc = 0;
+    goto out;
+
+ out:
+    if ( (rc != 0) && (dom != 0) )
+        xc_domain_destroy(xc_handle, dom);
+    free(p2m);
+
+    DPRINTF("Restore exit with rc=%d\n", rc);
+
+    return rc;
 }

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