From: Alexander Duyck <alexander.duyck@gmail.com>
To: Lan Tianyu <tianyu.lan@intel.com>,
bhelgaas@google.com, carolyn.wyborny@intel.com,
donald.c.skidmore@intel.com, eddie.dong@intel.com,
nrupal.jani@intel.com, yang.z.zhang@intel.com, agraf@suse.de,
kvm@vger.kernel.org, pbonzini@redhat.com, qemu-devel@nongnu.org,
emil.s.tantilov@intel.com, intel-wired-lan@lists.osuosl.org,
jeffrey.t.kirsher@intel.com, jesse.brandeburg@intel.com,
john.ronciak@intel.com, linux-kernel@vger.kernel.org,
linux-pci@vger.kernel.org, matthew.vick@intel.com,
mitch.a.williams@intel.com, netdev@vger.kernel.org,
shannon.nelson@intel.com
Subject: Re: [Qemu-devel] [RFC Patch 06/12] IXGBEVF: Add self emulation layer
Date: Wed, 21 Oct 2015 13:58:19 -0700 [thread overview]
Message-ID: <5627FC6B.8060004@gmail.com> (raw)
In-Reply-To: <1445445464-5056-7-git-send-email-tianyu.lan@intel.com>
On 10/21/2015 09:37 AM, Lan Tianyu wrote:
> In order to restore VF function after migration, add self emulation layer
> to record regs' values during accessing regs.
>
> Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
> ---
> drivers/net/ethernet/intel/ixgbevf/Makefile | 3 ++-
> drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c | 2 +-
> .../net/ethernet/intel/ixgbevf/self-emulation.c | 26 ++++++++++++++++++++++
> drivers/net/ethernet/intel/ixgbevf/vf.h | 5 ++++-
> 4 files changed, 33 insertions(+), 3 deletions(-)
> create mode 100644 drivers/net/ethernet/intel/ixgbevf/self-emulation.c
>
> diff --git a/drivers/net/ethernet/intel/ixgbevf/Makefile b/drivers/net/ethernet/intel/ixgbevf/Makefile
> index 4ce4c97..841c884 100644
> --- a/drivers/net/ethernet/intel/ixgbevf/Makefile
> +++ b/drivers/net/ethernet/intel/ixgbevf/Makefile
> @@ -31,7 +31,8 @@
>
> obj-$(CONFIG_IXGBEVF) += ixgbevf.o
>
> -ixgbevf-objs := vf.o \
> +ixgbevf-objs := self-emulation.o \
> + vf.o \
> mbx.o \
> ethtool.o \
> ixgbevf_main.o
> diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
> index a16d267..4446916 100644
> --- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
> +++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
> @@ -156,7 +156,7 @@ u32 ixgbevf_read_reg(struct ixgbe_hw *hw, u32 reg)
>
> if (IXGBE_REMOVED(reg_addr))
> return IXGBE_FAILED_READ_REG;
> - value = readl(reg_addr + reg);
> + value = ixgbe_self_emul_readl(reg_addr, reg);
> if (unlikely(value == IXGBE_FAILED_READ_REG))
> ixgbevf_check_remove(hw, reg);
> return value;
> diff --git a/drivers/net/ethernet/intel/ixgbevf/self-emulation.c b/drivers/net/ethernet/intel/ixgbevf/self-emulation.c
> new file mode 100644
> index 0000000..d74b2da
> --- /dev/null
> +++ b/drivers/net/ethernet/intel/ixgbevf/self-emulation.c
> @@ -0,0 +1,26 @@
> +#include <linux/netdevice.h>
> +#include <linux/pci.h>
> +#include <linux/delay.h>
> +#include <linux/interrupt.h>
> +#include <net/arp.h>
> +
> +#include "vf.h"
> +#include "ixgbevf.h"
> +
> +static u32 hw_regs[0x4000];
> +
> +u32 ixgbe_self_emul_readl(volatile void __iomem *base, u32 addr)
> +{
> + u32 tmp;
> +
> + tmp = readl(base + addr);
> + hw_regs[(unsigned long)addr] = tmp;
> +
> + return tmp;
> +}
> +
> +void ixgbe_self_emul_writel(u32 val, volatile void __iomem *base, u32 addr)
> +{
> + hw_regs[(unsigned long)addr] = val;
> + writel(val, (volatile void __iomem *)(base + addr));
> +}
So I see what you are doing, however I don't think this adds much
value. Many of the key registers for the device are not simple
Read/Write registers. Most of them are things like write 1 to clear or
some other sort of value where writing doesn't set the bit but has some
other side effect. Just take a look through the Datasheet at registers
such as the VFCTRL, VFMAILBOX, or most of the interrupt registers. The
fact is simply storing the values off doesn't give you any real idea of
what the state of things are.
> diff --git a/drivers/net/ethernet/intel/ixgbevf/vf.h b/drivers/net/ethernet/intel/ixgbevf/vf.h
> index d40f036..6a3f4eb 100644
> --- a/drivers/net/ethernet/intel/ixgbevf/vf.h
> +++ b/drivers/net/ethernet/intel/ixgbevf/vf.h
> @@ -39,6 +39,9 @@
>
> struct ixgbe_hw;
>
> +u32 ixgbe_self_emul_readl(volatile void __iomem *base, u32 addr);
> +void ixgbe_self_emul_writel(u32 val, volatile void __iomem *base, u32 addr);
> +
> /* iterator type for walking multicast address lists */
> typedef u8* (*ixgbe_mc_addr_itr) (struct ixgbe_hw *hw, u8 **mc_addr_ptr,
> u32 *vmdq);
> @@ -182,7 +185,7 @@ static inline void ixgbe_write_reg(struct ixgbe_hw *hw, u32 reg, u32 value)
>
> if (IXGBE_REMOVED(reg_addr))
> return;
> - writel(value, reg_addr + reg);
> + ixgbe_self_emul_writel(value, reg_addr, reg);
> }
>
> #define IXGBE_WRITE_REG(h, r, v) ixgbe_write_reg(h, r, v)
next prev parent reply other threads:[~2015-10-21 20:58 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-21 16:37 [Qemu-devel] [RFC Patch 00/12] IXGBE: Add live migration support for SRIOV NIC Lan Tianyu
2015-10-21 16:37 ` [Qemu-devel] [RFC Patch 01/12] PCI: Add virtfn_index for struct pci_device Lan Tianyu
2015-10-21 18:07 ` Alexander Duyck
2015-10-24 14:46 ` Lan, Tianyu
2015-10-21 16:37 ` [Qemu-devel] [RFC Patch 02/12] IXGBE: Add new mail box event to restore VF status in the PF driver Lan Tianyu
2015-10-21 20:34 ` Alexander Duyck
2015-10-21 16:37 ` [Qemu-devel] [RFC Patch 03/12] IXGBE: Add sysfs interface for Qemu to migrate " Lan Tianyu
2015-10-21 20:45 ` Alexander Duyck
2015-10-25 7:21 ` Lan, Tianyu
2015-10-21 16:37 ` [Qemu-devel] [RFC Patch 04/12] IXGBE: Add ixgbe_ping_vf() to notify a specified VF via mailbox msg Lan Tianyu
2015-10-21 16:37 ` [Qemu-devel] [RFC Patch 05/12] IXGBE: Add new sysfs interface of "notify_vf" Lan Tianyu
2015-10-21 20:52 ` Alexander Duyck
2015-10-22 12:51 ` Michael S. Tsirkin
2015-10-24 15:43 ` Lan, Tianyu
2015-10-25 6:03 ` Alexander Duyck
2015-10-25 6:45 ` Lan, Tianyu
2015-10-21 16:37 ` [Qemu-devel] [RFC Patch 06/12] IXGBEVF: Add self emulation layer Lan Tianyu
2015-10-21 20:58 ` Alexander Duyck [this message]
2015-10-22 12:50 ` Michael S. Tsirkin
2015-10-22 15:50 ` Alexander Duyck
2015-10-21 16:37 ` [Qemu-devel] [RFC Patch 07/12] IXGBEVF: Add new mail box event for migration Lan Tianyu
2015-10-21 16:37 ` [Qemu-devel] [RFC Patch 08/12] IXGBEVF: Rework code of finding the end transmit desc of package Lan Tianyu
2015-10-21 21:14 ` Alexander Duyck
2015-10-24 16:12 ` Lan, Tianyu
2015-10-22 12:58 ` Michael S. Tsirkin
2015-10-24 16:08 ` Lan, Tianyu
2015-10-21 16:37 ` [Qemu-devel] [RFC Patch 09/12] IXGBEVF: Add live migration support for VF driver Lan Tianyu
2015-10-21 21:48 ` Alexander Duyck
2015-10-22 12:46 ` Michael S. Tsirkin
2015-10-21 16:37 ` [Qemu-devel] [RFC Patch 10/12] IXGBEVF: Add lock to protect tx/rx ring operation Lan Tianyu
2015-10-21 21:55 ` Alexander Duyck
2015-10-22 12:40 ` Michael S. Tsirkin
2015-10-21 16:37 ` [Qemu-devel] [RFC Patch 11/12] IXGBEVF: Migrate VF statistic data Lan Tianyu
2015-10-22 12:36 ` Michael S. Tsirkin
2015-10-21 16:37 ` [Qemu-devel] [RFC Patch 12/12] IXGBEVF: Track dma dirty pages Lan Tianyu
2015-10-22 12:30 ` Michael S. Tsirkin
2015-10-21 18:45 ` [Qemu-devel] [RFC Patch 00/12] IXGBE: Add live migration support for SRIOV NIC Or Gerlitz
2015-10-21 19:20 ` Alex Williamson
2015-10-21 23:26 ` Alexander Duyck
2015-10-22 12:32 ` Michael S. Tsirkin
2015-10-22 13:01 ` Alex Williamson
2015-10-22 13:06 ` Michael S. Tsirkin
2015-10-22 15:58 ` Or Gerlitz
2015-10-22 16:17 ` Alex Williamson
2015-10-22 12:55 ` Michael S. Tsirkin
2015-10-23 18:36 ` Alexander Duyck
2015-10-23 19:05 ` Alex Williamson
2015-10-23 20:01 ` Alexander Duyck
2015-10-26 5:36 ` Lan Tianyu
2015-10-26 15:03 ` Alexander Duyck
2015-10-29 6:12 ` Lan Tianyu
2015-10-29 6:58 ` Alexander Duyck
2015-10-29 8:33 ` Lan Tianyu
2015-10-29 16:17 ` Alexander Duyck
2015-10-30 2:41 ` Lan Tianyu
2015-10-30 18:04 ` Alexander Duyck
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