Re: [PATCH V9 9/9] virtio: Intel IFC VF driver for VDPA
From: Zhu, Lingshan
Date: Thu Apr 09 2020 - 23:16:04 EST
On 4/10/2020 4:25 AM, Michael S. Tsirkin wrote:
On Thu, Apr 09, 2020 at 12:41:13PM +0200, Arnd Bergmann wrote:
On Thu, Mar 26, 2020 at 3:08 PM Jason Wang <jasowang@xxxxxxxxxx> wrote:
From: Zhu Lingshan <lingshan.zhu@xxxxxxxxx>
This commit introduced two layers to drive IFC VF:
(1) ifcvf_base layer, which handles IFC VF NIC hardware operations and
configurations.
(2) ifcvf_main layer, which complies to VDPA bus framework,
implemented device operations for VDPA bus, handles device probe,
bus attaching, vring operations, etc.
Signed-off-by: Zhu Lingshan <lingshan.zhu@xxxxxxxxx>
Signed-off-by: Bie Tiwei <tiwei.bie@xxxxxxxxx>
Signed-off-by: Wang Xiao <xiao.w.wang@xxxxxxxxx>
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
+
+#define IFCVF_QUEUE_ALIGNMENT PAGE_SIZE
+#define IFCVF_QUEUE_MAX 32768
+static u16 ifcvf_vdpa_get_vq_align(struct vdpa_device *vdpa_dev)
+{
+ return IFCVF_QUEUE_ALIGNMENT;
+}
This fails to build on arm64 with 64kb page size (found in linux-next):
/drivers/vdpa/ifcvf/ifcvf_main.c: In function 'ifcvf_vdpa_get_vq_align':
arch/arm64/include/asm/page-def.h:17:20: error: conversion from 'long
unsigned int' to 'u16' {aka 'short unsigned int'} changes value from
'65536' to '0' [-Werror=overflow]
17 | #define PAGE_SIZE (_AC(1, UL) << PAGE_SHIFT)
| ^
drivers/vdpa/ifcvf/ifcvf_base.h:37:31: note: in expansion of macro 'PAGE_SIZE'
37 | #define IFCVF_QUEUE_ALIGNMENT PAGE_SIZE
| ^~~~~~~~~
drivers/vdpa/ifcvf/ifcvf_main.c:231:9: note: in expansion of macro
'IFCVF_QUEUE_ALIGNMENT'
231 | return IFCVF_QUEUE_ALIGNMENT;
| ^~~~~~~~~~~~~~~~~~~~~
It's probably good enough to just not allow the driver to be built in that
configuration as it's fairly rare but unfortunately there is no simple Kconfig
symbol for it.
In a similar driver, we did
config VMXNET3
tristate "VMware VMXNET3 ethernet driver"
depends on PCI && INET
depends on !(PAGE_SIZE_64KB || ARM64_64K_PAGES || \
IA64_PAGE_SIZE_64KB || MICROBLAZE_64K_PAGES || \
PARISC_PAGE_SIZE_64KB || PPC_64K_PAGES)
I think we should probably make PAGE_SIZE_64KB a global symbol
in arch/Kconfig and have it selected by the other symbols so drivers
like yours can add a dependency for it.
Arnd
It's probably easier to make the alignment u32 - I don't really know why it's
u16, all callers seem to assign the result to a u32 value.
Thanks Michael!
@ Arnd, would you please kindly have a try on the attached patch? I
failed to find an armv8 or above platform for now.
Thanks
BR
Zhu Lingshan
From bb2019f0620609fbbdc6854bccc5fefdb53f3d9d Mon Sep 17 00:00:00 2001
From: Zhu Lingshan <lingshan.zhu@xxxxxxxxx>
Date: Fri, 10 Apr 2020 11:04:38 +0800
Subject: [PATCH] vdpa: change get_vq_align() to u32 alignment
This commit change the return value of get_vq_align() to u32. this
can help resolve a build issue of arm64 platform, and adapting to
the callers.
Signed-off-by: Zhu Lingshan <lingshan.zhu@xxxxxxxxx>
---
drivers/vdpa/ifcvf/ifcvf_main.c | 2 +-
drivers/vdpa/vdpa_sim/vdpa_sim.c | 2 +-
include/linux/vdpa.h | 2 +-
3 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
index 8d54dc5..970895c 100644
--- a/drivers/vdpa/ifcvf/ifcvf_main.c
+++ b/drivers/vdpa/ifcvf/ifcvf_main.c
@@ -228,7 +228,7 @@ static u32 ifcvf_vdpa_get_vendor_id(struct vdpa_device *vdpa_dev)
return IFCVF_SUBSYS_VENDOR_ID;
}
-static u16 ifcvf_vdpa_get_vq_align(struct vdpa_device *vdpa_dev)
+static u32 ifcvf_vdpa_get_vq_align(struct vdpa_device *vdpa_dev)
{
return IFCVF_QUEUE_ALIGNMENT;
}
diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index 6e8a0cf..a4b3f0d 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -435,7 +435,7 @@ static u64 vdpasim_get_vq_state(struct vdpa_device *vdpa, u16 idx)
return vrh->last_avail_idx;
}
-static u16 vdpasim_get_vq_align(struct vdpa_device *vdpa)
+static u32 vdpasim_get_vq_align(struct vdpa_device *vdpa)
{
return VDPASIM_QUEUE_ALIGN;
}
diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
index 733acfb..5453af8 100644
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -164,7 +164,7 @@ struct vdpa_config_ops {
u64 (*get_vq_state)(struct vdpa_device *vdev, u16 idx);
/* Device ops */
- u16 (*get_vq_align)(struct vdpa_device *vdev);
+ u32 (*get_vq_align)(struct vdpa_device *vdev);
u64 (*get_features)(struct vdpa_device *vdev);
int (*set_features)(struct vdpa_device *vdev, u64 features);
void (*set_config_cb)(struct vdpa_device *vdev,
--
1.8.3.1