From 2f152d27eecc91b27383652a88400cfb6b48977a Mon Sep 17 00:00:00 2001
From: Xiao Wang <jasowang@redhat.com>
Date: Tue, 7 Jul 2015 09:18:40 +0200
Subject: [PATCH 152/217] virtio: add modern config accessors

Message-id: <1436260751-25015-38-git-send-email-jasowang@redhat.com>
Patchwork-id: 66812
O-Subject: [RHEL7.2 qemu-kvm-rhev PATCH V2 37/68] virtio: add modern config accessors
Bugzilla: 1227343
RH-Acked-by: Michael S. Tsirkin <mst@redhat.com>
RH-Acked-by: David Gibson <dgibson@redhat.com>
RH-Acked-by: Laurent Vivier <lvivier@redhat.com>
RH-Acked-by: Thomas Huth <thuth@redhat.com>

From: "Michael S. Tsirkin" <mst@redhat.com>

virtio 1.0 defines config space as LE,
as opposed to pre-1.0 which was native endian.

Add API for transports to execute word/dword accesses in
little endian format - will be useful for mmio
and pci (byte access is also wrapped, for completeness).

For simplicity, we still keep config in host native
endian format, byteswap to LE on guest access.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

(cherry picked from commit adfb743c90c7aa5e92907ce875e4f35747ee1963)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 hw/virtio/virtio.c         | 96 ++++++++++++++++++++++++++++++++++++++++++++++
 include/hw/virtio/virtio.h |  9 +++++
 2 files changed, 105 insertions(+)

diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index cae5eca..fb49ffc 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -729,6 +729,102 @@ void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data)
     }
 }
 
+uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr)
+{
+    VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
+    uint8_t val;
+
+    if (addr + sizeof(val) > vdev->config_len) {
+        return (uint32_t)-1;
+    }
+
+    k->get_config(vdev, vdev->config);
+
+    val = ldub_p(vdev->config + addr);
+    return val;
+}
+
+uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr)
+{
+    VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
+    uint16_t val;
+
+    if (addr + sizeof(val) > vdev->config_len) {
+        return (uint32_t)-1;
+    }
+
+    k->get_config(vdev, vdev->config);
+
+    val = lduw_le_p(vdev->config + addr);
+    return val;
+}
+
+uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr)
+{
+    VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
+    uint32_t val;
+
+    if (addr + sizeof(val) > vdev->config_len) {
+        return (uint32_t)-1;
+    }
+
+    k->get_config(vdev, vdev->config);
+
+    val = ldl_le_p(vdev->config + addr);
+    return val;
+}
+
+void virtio_config_modern_writeb(VirtIODevice *vdev,
+                                 uint32_t addr, uint32_t data)
+{
+    VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
+    uint8_t val = data;
+
+    if (addr + sizeof(val) > vdev->config_len) {
+        return;
+    }
+
+    stb_p(vdev->config + addr, val);
+
+    if (k->set_config) {
+        k->set_config(vdev, vdev->config);
+    }
+}
+
+void virtio_config_modern_writew(VirtIODevice *vdev,
+                                 uint32_t addr, uint32_t data)
+{
+    VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
+    uint16_t val = data;
+
+    if (addr + sizeof(val) > vdev->config_len) {
+        return;
+    }
+
+    stw_le_p(vdev->config + addr, val);
+
+    if (k->set_config) {
+        k->set_config(vdev, vdev->config);
+    }
+}
+
+void virtio_config_modern_writel(VirtIODevice *vdev,
+                                 uint32_t addr, uint32_t data)
+{
+    VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
+    uint32_t val = data;
+
+    if (addr + sizeof(val) > vdev->config_len) {
+        return;
+    }
+
+    stl_le_p(vdev->config + addr, val);
+
+    if (k->set_config) {
+        k->set_config(vdev, vdev->config);
+    }
+}
+
 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr)
 {
     vdev->vq[n].vring.desc = addr;
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index 96a32a1..2bf9cc1 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -174,6 +174,15 @@ uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr);
 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data);
 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data);
 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data);
+uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr);
+uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr);
+uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr);
+void virtio_config_modern_writeb(VirtIODevice *vdev,
+                                 uint32_t addr, uint32_t data);
+void virtio_config_modern_writew(VirtIODevice *vdev,
+                                 uint32_t addr, uint32_t data);
+void virtio_config_modern_writel(VirtIODevice *vdev,
+                                 uint32_t addr, uint32_t data);
 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr);
 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n);
 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num);
-- 
1.8.3.1