Re: [PATCH-for-8.0 v2 4/6] hw/virtio: Constify qmp_virtio_feature_map_t[]

[Jonah Palmer]

On 12/13/22 06:17, Philippe Mathieu-Daudé wrote:

These arrays are only accessed read-only, move them to .rodata.

Signed-off-by: Philippe Mathieu-Daudé<phi...@linaro.org>
---
  hw/virtio/virtio.c | 34 +++++++++++++++++-----------------
  1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index b35480be8f..f2298bb437 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -80,7 +80,7 @@ enum VhostUserProtocolFeature {
  };

/* Virtio transport features mapping */

-static qmp_virtio_feature_map_t virtio_transport_map[] = {
+static const qmp_virtio_feature_map_t virtio_transport_map[] = {
      /* Virtio device transport features */
  #ifndef VIRTIO_CONFIG_NO_LEGACY
      FEATURE_ENTRY(VIRTIO_F_NOTIFY_ON_EMPTY, \
@@ -111,7 +111,7 @@ static qmp_virtio_feature_map_t virtio_transport_map[] = {
  };

/* Vhost-user protocol features mapping */

-static qmp_virtio_feature_map_t vhost_user_protocol_map[] = {
+static const qmp_virtio_feature_map_t vhost_user_protocol_map[] = {
      FEATURE_ENTRY(VHOST_USER_PROTOCOL_F_MQ, \
              "VHOST_USER_PROTOCOL_F_MQ: Multiqueue protocol supported"),
      FEATURE_ENTRY(VHOST_USER_PROTOCOL_F_LOG_SHMFD, \
@@ -161,7 +161,7 @@ static qmp_virtio_feature_map_t vhost_user_protocol_map[] = 
{
  };

/* virtio device configuration statuses */

-static qmp_virtio_feature_map_t virtio_config_status_map[] = {
+static const qmp_virtio_feature_map_t virtio_config_status_map[] = {
      FEATURE_ENTRY(VIRTIO_CONFIG_S_DRIVER_OK, \
              "VIRTIO_CONFIG_S_DRIVER_OK: Driver setup and ready"),
      FEATURE_ENTRY(VIRTIO_CONFIG_S_FEATURES_OK, \
@@ -180,7 +180,7 @@ static qmp_virtio_feature_map_t virtio_config_status_map[] 
= {

/* virtio-blk features mapping */

  #ifdef CONFIG_VIRTIO_BLK
-static qmp_virtio_feature_map_t virtio_blk_feature_map[] = {
+static const qmp_virtio_feature_map_t virtio_blk_feature_map[] = {
      FEATURE_ENTRY(VIRTIO_BLK_F_SIZE_MAX, \
              "VIRTIO_BLK_F_SIZE_MAX: Max segment size is size_max"),
      FEATURE_ENTRY(VIRTIO_BLK_F_SEG_MAX, \
@@ -221,7 +221,7 @@ static qmp_virtio_feature_map_t virtio_blk_feature_map[] = {

/* virtio-serial features mapping */

  #ifdef CONFIG_VIRTIO_SERIAL
-static qmp_virtio_feature_map_t virtio_serial_feature_map[] = {
+static const qmp_virtio_feature_map_t virtio_serial_feature_map[] = {
      FEATURE_ENTRY(VIRTIO_CONSOLE_F_SIZE, \
              "VIRTIO_CONSOLE_F_SIZE: Host providing console size"),
      FEATURE_ENTRY(VIRTIO_CONSOLE_F_MULTIPORT, \
@@ -234,7 +234,7 @@ static qmp_virtio_feature_map_t virtio_serial_feature_map[] 
= {

/* virtio-gpu features mapping */

  #ifdef CONFIG_VIRTIO_GPU
-static qmp_virtio_feature_map_t virtio_gpu_feature_map[] = {
+static const qmp_virtio_feature_map_t virtio_gpu_feature_map[] = {
      FEATURE_ENTRY(VIRTIO_GPU_F_VIRGL, \
              "VIRTIO_GPU_F_VIRGL: Virgl 3D mode supported"),
      FEATURE_ENTRY(VIRTIO_GPU_F_EDID, \
@@ -257,7 +257,7 @@ static qmp_virtio_feature_map_t virtio_gpu_feature_map[] = {

/* virtio-input features mapping */

  #ifdef CONFIG_VIRTIO_INPUT
-static qmp_virtio_feature_map_t virtio_input_feature_map[] = {
+static const qmp_virtio_feature_map_t virtio_input_feature_map[] = {
      FEATURE_ENTRY(VHOST_F_LOG_ALL, \
              "VHOST_F_LOG_ALL: Logging write descriptors supported"),
      FEATURE_ENTRY(VHOST_USER_F_PROTOCOL_FEATURES, \
@@ -269,7 +269,7 @@ static qmp_virtio_feature_map_t virtio_input_feature_map[] 
= {

/* virtio-net features mapping */

  #ifdef CONFIG_VIRTIO_NET
-static qmp_virtio_feature_map_t virtio_net_feature_map[] = {
+static const qmp_virtio_feature_map_t virtio_net_feature_map[] = {
      FEATURE_ENTRY(VIRTIO_NET_F_CSUM, \
              "VIRTIO_NET_F_CSUM: Device handling packets with partial checksum 
"
              "supported"),
@@ -349,7 +349,7 @@ static qmp_virtio_feature_map_t virtio_net_feature_map[] = {

/* virtio-scsi features mapping */

  #ifdef CONFIG_VIRTIO_SCSI
-static qmp_virtio_feature_map_t virtio_scsi_feature_map[] = {
+static const qmp_virtio_feature_map_t virtio_scsi_feature_map[] = {
      FEATURE_ENTRY(VIRTIO_SCSI_F_INOUT, \
              "VIRTIO_SCSI_F_INOUT: Requests including read and writable data "
              "buffers suppoted"),
@@ -372,7 +372,7 @@ static qmp_virtio_feature_map_t virtio_scsi_feature_map[] = 
{

/* virtio/vhost-user-fs features mapping */

  #ifdef CONFIG_VHOST_USER_FS
-static qmp_virtio_feature_map_t virtio_fs_feature_map[] = {
+static const qmp_virtio_feature_map_t virtio_fs_feature_map[] = {
      FEATURE_ENTRY(VHOST_F_LOG_ALL, \
              "VHOST_F_LOG_ALL: Logging write descriptors supported"),
      FEATURE_ENTRY(VHOST_USER_F_PROTOCOL_FEATURES, \
@@ -384,7 +384,7 @@ static qmp_virtio_feature_map_t virtio_fs_feature_map[] = {

/* virtio/vhost-user-i2c features mapping */

  #ifdef CONFIG_VIRTIO_I2C_ADAPTER
-static qmp_virtio_feature_map_t virtio_i2c_feature_map[] = {
+static const qmp_virtio_feature_map_t virtio_i2c_feature_map[] = {
      FEATURE_ENTRY(VIRTIO_I2C_F_ZERO_LENGTH_REQUEST, \
              "VIRTIO_I2C_F_ZERO_LEGNTH_REQUEST: Zero length requests 
supported"),
      FEATURE_ENTRY(VHOST_F_LOG_ALL, \
@@ -398,7 +398,7 @@ static qmp_virtio_feature_map_t virtio_i2c_feature_map[] = {

/* virtio/vhost-vsock features mapping */

  #ifdef CONFIG_VHOST_VSOCK
-static qmp_virtio_feature_map_t virtio_vsock_feature_map[] = {
+static const qmp_virtio_feature_map_t virtio_vsock_feature_map[] = {
      FEATURE_ENTRY(VIRTIO_VSOCK_F_SEQPACKET, \
              "VIRTIO_VSOCK_F_SEQPACKET: SOCK_SEQPACKET supported"),
      FEATURE_ENTRY(VHOST_F_LOG_ALL, \
@@ -412,7 +412,7 @@ static qmp_virtio_feature_map_t virtio_vsock_feature_map[] 
= {

/* virtio-balloon features mapping */

  #ifdef CONFIG_VIRTIO_BALLOON
-static qmp_virtio_feature_map_t virtio_balloon_feature_map[] = {
+static const qmp_virtio_feature_map_t virtio_balloon_feature_map[] = {
      FEATURE_ENTRY(VIRTIO_BALLOON_F_MUST_TELL_HOST, \
              "VIRTIO_BALLOON_F_MUST_TELL_HOST: Tell host before reclaiming "
              "pages"),
@@ -432,7 +432,7 @@ static qmp_virtio_feature_map_t 
virtio_balloon_feature_map[] = {

/* virtio-crypto features mapping */

  #ifdef CONFIG_VIRTIO_CRYPTO
-static qmp_virtio_feature_map_t virtio_crypto_feature_map[] = {
+static const qmp_virtio_feature_map_t virtio_crypto_feature_map[] = {
      FEATURE_ENTRY(VHOST_F_LOG_ALL, \
              "VHOST_F_LOG_ALL: Logging write descriptors supported"),
      { -1, "" }
@@ -441,7 +441,7 @@ static qmp_virtio_feature_map_t virtio_crypto_feature_map[] 
= {

/* virtio-iommu features mapping */

  #ifdef CONFIG_VIRTIO_IOMMU
-static qmp_virtio_feature_map_t virtio_iommu_feature_map[] = {
+static const qmp_virtio_feature_map_t virtio_iommu_feature_map[] = {
      FEATURE_ENTRY(VIRTIO_IOMMU_F_INPUT_RANGE, \
              "VIRTIO_IOMMU_F_INPUT_RANGE: Range of available virtual addrs. "
              "available"),
@@ -466,7 +466,7 @@ static qmp_virtio_feature_map_t virtio_iommu_feature_map[] 
= {

/* virtio-mem features mapping */

  #ifdef CONFIG_VIRTIO_MEM
-static qmp_virtio_feature_map_t virtio_mem_feature_map[] = {
+static const qmp_virtio_feature_map_t virtio_mem_feature_map[] = {
  #ifndef CONFIG_ACPI
      FEATURE_ENTRY(VIRTIO_MEM_F_ACPI_PXM, \
              "VIRTIO_MEM_F_ACPI_PXM: node_id is an ACPI PXM and is valid"),
@@ -480,7 +480,7 @@ static qmp_virtio_feature_map_t virtio_mem_feature_map[] = {

/* virtio-rng features mapping */

  #ifdef CONFIG_VIRTIO_RNG
-static qmp_virtio_feature_map_t virtio_rng_feature_map[] = {
+static const qmp_virtio_feature_map_t virtio_rng_feature_map[] = {
      FEATURE_ENTRY(VHOST_F_LOG_ALL, \
              "VHOST_F_LOG_ALL: Logging write descriptors supported"),
      FEATURE_ENTRY(VHOST_USER_F_PROTOCOL_FEATURES, \

Also a good catch. These maps should not change after being initialized,
since they're just definitions. Adding const here appears to be appropriate.

Reviewed-by: Jonah Palmer<jonah.pal...@oracle.com>