support for live migration region and dirty page logging

This patch adds support for the live migration region and dirty page logging
following VFIO. Live migration is NOT yet functional as handling accesses to
the migration region is not yet implemented. Currenty the live migration region
is fixed at index 9 simply for simplifying the implementation. Dirty page
logging is simplified by requiring IOVA ranges to match exactly the entire IOVA
range.

Signed-off-by: Thanos Makatos <thanos.makatos@nutanix.com>

1 files changed, 21 insertions, 2 deletions

diff --git a/samples/server.c b/samples/server.c
index 782ccdc..9f4d3b1 100644
--- a/samples/server.c
+++ b/samples/server.c
@@ -39,6 +39,7 @@
 #include <time.h>
 #include <assert.h>
 #include <openssl/md5.h>
+#include <sys/mman.h>
 
 #include "../lib/muser.h"
 
@@ -146,17 +147,30 @@ void get_md5sum(char *buf, int len, char *md5sum)
     return;
 }
 
+/*
+ * FIXME this function does DMA write/read using messages. This should be done
+ * on a region that is not memory mappable or an area of a region that is not
+ * sparsely memory mappable. We should also have a test where the server does
+ * DMA directly on the client memory.
+ */
 static int do_dma_io(lm_ctx_t *lm_ctx, struct server_data *server_data)
 {
     int count = 4096;
     char buf[count], md5sum1[MD5_DIGEST_LENGTH], md5sum2[MD5_DIGEST_LENGTH];
     int i, ret;
+    dma_sg_t sg;
+
+    assert(lm_ctx != NULL);
+
+    ret = lm_addr_to_sg(lm_ctx, server_data->regions[0].addr, count, &sg,
+                        1, PROT_WRITE);
+    assert(ret == 1); /* FIXME */
 
     memset(buf, 'A', count);
     get_md5sum(buf, count, md5sum1);
     printf("%s: WRITE addr %#lx count %llu\n", __func__,
            server_data->regions[0].addr, count);
-    ret = lm_dma_write(lm_ctx, server_data->regions[0].addr, count, buf);
+    ret = lm_dma_write(lm_ctx, &sg, buf);
     if (ret < 0) {
         fprintf(stderr, "lm_dma_write failed: %s\n", strerror(-ret));
         return ret;
@@ -165,7 +179,7 @@ static int do_dma_io(lm_ctx_t *lm_ctx, struct server_data *server_data)
     memset(buf, 0, count);
     printf("%s: READ  addr %#lx count %llu\n", __func__,
 	   server_data->regions[0].addr, count);
-    ret = lm_dma_read(lm_ctx, server_data->regions[0].addr, count, buf);
+    ret = lm_dma_read(lm_ctx, &sg, buf);
     if (ret < 0) {
         fprintf(stderr, "lm_dma_read failed: %s\n", strerror(-ret));
         return ret;
@@ -253,6 +267,11 @@ int main(int argc, char *argv[])
                 .mmap_areas = sparse_areas,
 		        .map = map_area
             },
+            .reg_info[LM_DEV_MIGRATION_REG_IDX] = { /* migration region */
+                .flags = LM_REG_FLAG_RW,
+                .size = sysconf(_SC_PAGESIZE),
+                .mmap_areas = sparse_areas,
+            },
             .irq_count[LM_DEV_INTX_IRQ_IDX] = 1,
         },
         .uuid = argv[optind],