[SeaBIOS] [PATCH v2] src/hw/virtio-blk: add feature VIRTIO_BLK_F_SIZE_MAX and VIRTIO_BLK_F_SEG_MAX

[Andy Pei]

according to virtio spec, add feature VIRTIO_BLK_F_SIZE_MAX
and VIRTIO_BLK_F_SEG_MAX parse to virtio blk driver.

Signed-off-by: Ding Limin 
Signed-off-by: Andy Pei 
---
 src/block.h         |  2 ++
 src/hw/virtio-blk.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++--
 src/hw/virtio-blk.h |  3 +++
 3 files changed, 59 insertions(+), 2 deletions(-)

diff --git a/src/block.h b/src/block.h
index c1b8d73..3af2d71 100644
--- a/src/block.h
+++ b/src/block.h
@@ -57,6 +57,8 @@ struct drive_s {
     u8 translation;     // type of translation
     u16 blksize;        // block size
     struct chs_s pchs;  // Physical CHS
+    u32 max_segment_size; //max_segment_size
+    u32 max_segments;   //max_segments
 };

#define DISK_SECTOR_SIZE  512
diff --git a/src/hw/virtio-blk.c b/src/hw/virtio-blk.c
index 3b19896..7935f0f 100644
--- a/src/hw/virtio-blk.c
+++ b/src/hw/virtio-blk.c
@@ -121,12 +121,16 @@ init_virtio_blk(void *data)
         u64 version1 = 1ull << VIRTIO_F_VERSION_1;
         u64 iommu_platform = 1ull << VIRTIO_F_IOMMU_PLATFORM;
         u64 blk_size = 1ull << VIRTIO_BLK_F_BLK_SIZE;
+        u64 max_segments = 1ull << VIRTIO_BLK_F_SEG_MAX;
+        u64 max_segment_size = 1ull << VIRTIO_BLK_F_SIZE_MAX;
+
         if (!(features & version1)) {
             dprintf(1, "modern device without virtio_1 feature bit: %pP\n", pci);
             goto fail;
         }

-        features = features & (version1 | iommu_platform | blk_size);
+        features = features & (version1 | iommu_platform | blk_size
+                        | max_segments | max_segment_size);
         vp_set_features(vp, features);
         status |= VIRTIO_CONFIG_S_FEATURES_OK;
         vp_set_status(vp, status);
@@ -135,6 +139,22 @@ init_virtio_blk(void *data)
             goto fail;
         }

+        if (features & max_segment_size)
+            vdrive->drive.max_segment_size =
+                vp_read(&vp->device, struct virtio_blk_config, size_max);
+        else
+            vdrive->drive.max_segment_size = 0;
+        dprintf(3, "virtio-blk %pP size_max=%u.\n", pci,
+                vdrive->drive.max_segment_size);
+
+        if (features & max_segments)
+            vdrive->drive.max_segments =
+                vp_read(&vp->device, struct virtio_blk_config, seg_max);
+        else
+            vdrive->drive.max_segments = 0;
+        dprintf(3, "virtio-blk %pP seg_max=%u.\n", pci,
+                vdrive->drive.max_segments);
+
         vdrive->drive.sectors =
             vp_read(&vp->device, struct virtio_blk_config, capacity);
         if (features & blk_size) {
@@ -177,6 +197,21 @@ init_virtio_blk(void *data)
         vdrive->drive.pchs.cylinder = cfg.cylinders;
         vdrive->drive.pchs.head = cfg.heads;
         vdrive->drive.pchs.sector = cfg.sectors;
+
+        if (f & (1 << VIRTIO_BLK_F_SIZE_MAX))
+            vdrive->drive.max_segment_size = cfg.size_max;
+        else
+            vdrive->drive.max_segment_size = 0;
+        dprintf(3, "virtio-blk %pP size_max=%u.\n", pci,
+                vdrive->drive.max_segment_size);
+
+        if (f & (1 << VIRTIO_BLK_F_SEG_MAX))
+            vdrive->drive.max_segments = cfg.seg_max;
+        else
+            vdrive->drive.max_segments = 0;
+        dprintf(3, "virtio-blk %pP seg_max=%u.\n", pci,
+                vdrive->drive.max_segments);
+
     }

char *desc = znprintf(MAXDESCSIZE, "Virtio disk PCI:%pP", pci);
@@ -218,8 +253,11 @@ init_virtio_blk_mmio(void *mmio)
     u64 features = vp_get_features(vp);
     u64 version1 = 1ull << VIRTIO_F_VERSION_1;
     u64 blk_size = 1ull << VIRTIO_BLK_F_BLK_SIZE;
+    u64 max_segments = 1ull << VIRTIO_BLK_F_SEG_MAX;
+    u64 max_segment_size = 1ull << VIRTIO_BLK_F_SIZE_MAX;

-    features = features & (version1 | blk_size);
+    features = features & (version1 | blk_size
+            | max_segments | max_segment_size);
     vp_set_features(vp, features);
     status |= VIRTIO_CONFIG_S_FEATURES_OK;
     vp_set_status(vp, status);
@@ -228,6 +266,20 @@ init_virtio_blk_mmio(void *mmio)
         goto fail;
     }

+    if (features & max_segment_size)
+        vdrive->drive.max_segment_size =
+            vp_read(&vp->device, struct virtio_blk_config, size_max);
+    else
+        vdrive->drive.max_segment_size = 0;
+    dprintf(3, "virtio-blk size_max=%u.\n", vdrive->drive.max_segment_size);
+
+    if (features & max_segments)
+        vdrive->drive.max_segments =
+            vp_read(&vp->device, struct virtio_blk_config, seg_max);
+    else
+        vdrive->drive.max_segments = 0;
+    dprintf(3, "virtio-blk seg_max=%u.\n", vdrive->drive.max_segments);
+
     vdrive->drive.sectors =
         vp_read(&vp->device, struct virtio_blk_config, capacity);
     if (features & blk_size) {
diff --git a/src/hw/virtio-blk.h b/src/hw/virtio-blk.h
index d20461a..0294291 100644
--- a/src/hw/virtio-blk.h
+++ b/src/hw/virtio-blk.h
@@ -16,6 +16,9 @@ struct virtio_blk_config
     u32 opt_io_size;
 } __attribute__((packed));

+/* Feature bits */
+#define VIRTIO_BLK_F_SIZE_MAX 1  /* Maximum size of any single segment */
+#define VIRTIO_BLK_F_SEG_MAX 2   /* Maximum number of segments in a request */
 #define VIRTIO_BLK_F_BLK_SIZE 6

/* These two define direction. */