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[Qemu-devel] [RFC PATCH 1/7] virtio: Add shared memory capability
From: |
Dr. David Alan Gilbert (git) |
Subject: |
[Qemu-devel] [RFC PATCH 1/7] virtio: Add shared memory capability |
Date: |
Mon, 10 Dec 2018 17:31:45 +0000 |
From: "Dr. David Alan Gilbert" <address@hidden>
Define a new capability type 'VIRTIO_PCI_CAP_SHARED_MEMORY_CFG'
and the data structure 'virtio_pci_shm_cap' to go with it.
They allow defining shared memory regions with sizes and offsets
of 2^32 and more.
Multiple instances of the capability are allowed and distinguished
by a device-specific 'id'.
Signed-off-by: Dr. David Alan Gilbert <address@hidden>
---
hw/virtio/virtio-pci.c | 20 ++++++++++++++++++++
include/standard-headers/linux/virtio_pci.h | 9 +++++++++
2 files changed, 29 insertions(+)
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index a954799267..1e737531b5 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1163,6 +1163,26 @@ static int virtio_pci_add_mem_cap(VirtIOPCIProxy *proxy,
return offset;
}
+static int virtio_pci_add_shm_cap(VirtIOPCIProxy *proxy,
+ uint8_t bar,
+ uint64_t offset, uint64_t length,
+ uint8_t id)
+{
+ struct virtio_pci_shm_cap cap = {
+ .cap.cap_len = sizeof cap,
+ .cap.cfg_type = VIRTIO_PCI_CAP_SHARED_MEMORY_CFG,
+ };
+ uint32_t mask32 = ~0;
+
+ cap.cap.bar = bar;
+ cap.cap.length = cpu_to_le32(length & mask32);
+ cap.length_hi = cpu_to_le32((length >> 32) & mask32);
+ cap.cap.offset = cpu_to_le32(offset & mask32);
+ cap.offset_hi = cpu_to_le32((offset >> 32) & mask32);
+ cap.id = id;
+ return virtio_pci_add_mem_cap(proxy, &cap.cap);
+}
+
static uint64_t virtio_pci_common_read(void *opaque, hwaddr addr,
unsigned size)
{
diff --git a/include/standard-headers/linux/virtio_pci.h
b/include/standard-headers/linux/virtio_pci.h
index 9262acd130..745d7a1942 100644
--- a/include/standard-headers/linux/virtio_pci.h
+++ b/include/standard-headers/linux/virtio_pci.h
@@ -113,6 +113,8 @@
#define VIRTIO_PCI_CAP_DEVICE_CFG 4
/* PCI configuration access */
#define VIRTIO_PCI_CAP_PCI_CFG 5
+/* Additional shared memory capability */
+#define VIRTIO_PCI_CAP_SHARED_MEMORY_CFG 8
/* This is the PCI capability header: */
struct virtio_pci_cap {
@@ -163,6 +165,13 @@ struct virtio_pci_cfg_cap {
uint8_t pci_cfg_data[4]; /* Data for BAR access. */
};
+struct virtio_pci_shm_cap {
+ struct virtio_pci_cap cap;
+ uint32_t offset_hi; /* Most sig 32 bits of offset */
+ uint32_t length_hi; /* Most sig 32 bits of length */
+ uint8_t id; /* To distinguish shm chunks */
+};
+
/* Macro versions of offsets for the Old Timers! */
#define VIRTIO_PCI_CAP_VNDR 0
#define VIRTIO_PCI_CAP_NEXT 1
--
2.19.2