linux/drivers/hv/ring_buffer.c, branch v5.14

scsi: storvsc: Use blk_mq_unique_tag() to generate requestIDs

2021-05-14T17:39:32Z

Use blk_mq_unique_tag() to generate requestIDs for StorVSC, avoiding all issues with allocating enough entries in the VMbus requestor. Suggested-by: Michael Kelley Signed-off-by: Andrea Parri (Microsoft) Reviewed-by: Michael Kelley Acked-by: Martin K. Petersen Link: https://lore.kernel.org/r/20210510210841.370472-1-parri.andrea@gmail.com Signed-off-by: Wei Liu

Drivers: hv: vmbus: Copy packets sent by Hyper-V out of the ring buffer

2021-05-14T17:37:46Z

Pointers to ring-buffer packets sent by Hyper-V are used within the guest VM. Hyper-V can send packets with erroneous values or modify packet fields after they are processed by the guest. To defend against these scenarios, return a copy of the incoming VMBus packet after validating its length and offset fields in hv_pkt_iter_first(). In this way, the packet can no longer be modified by the host. Signed-off-by: Andres Beltran Co-developed-by: Andrea Parri (Microsoft) Signed-off-by: Andrea Parri (Microsoft) Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20210408161439.341988-1-parri.andrea@gmail.com Signed-off-by: Wei Liu

Drivers: hv: vmbus: remove unused function

2021-04-14T15:14:02Z

Fix the following clang warning: drivers/hv/ring_buffer.c:89:1: warning: unused function 'hv_set_next_read_location' [-Wunused-function]. Reported-by: Abaci Robot Signed-off-by: Jiapeng Chong Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/1618381282-119135-1-git-send-email-jiapeng.chong@linux.alibaba.com Signed-off-by: Wei Liu

Drivers: hv: vmbus: Drop error message when 'No request id available'

2021-03-22T10:53:48Z

Running out of request IDs on a channel essentially produces the same effect as running out of space in the ring buffer, in that -EAGAIN is returned. The error message in hv_ringbuffer_write() should either be dropped (since we don't output a message when the ring buffer is full) or be made conditional/debug-only. Suggested-by: Michael Kelley Signed-off-by: Andrea Parri (Microsoft) Fixes: e8b7db38449ac ("Drivers: hv: vmbus: Add vmbus_requestor data structure for VMBus hardening") Link: https://lore.kernel.org/r/20210301191348.196485-1-parri.andrea@gmail.com Signed-off-by: Wei Liu

Drivers: hv: vmbus: Add vmbus_requestor data structure for VMBus hardening

2020-11-17T10:51:06Z

Currently, VMbus drivers use pointers into guest memory as request IDs for interactions with Hyper-V. To be more robust in the face of errors or malicious behavior from a compromised Hyper-V, avoid exposing guest memory addresses to Hyper-V. Also avoid Hyper-V giving back a bad request ID that is then treated as the address of a guest data structure with no validation. Instead, encapsulate these memory addresses and provide small integers as request IDs. Signed-off-by: Andres Beltran Co-developed-by: Andrea Parri (Microsoft) Signed-off-by: Andrea Parri (Microsoft) Reviewed-by: Michael Kelley Reviewed-by: Wei Liu Link: https://lore.kernel.org/r/20201109100402.8946-2-parri.andrea@gmail.com Signed-off-by: Wei Liu

drivers: hv: vmbus: Introduce latency testing

2019-11-22T01:10:44Z

Introduce user specified latency in the packet reception path By exposing the test parameters as part of the debugfs channel attributes. We will control the testing state via these attributes. Signed-off-by: Branden Bonaby Reviewed-by: Michael Kelley Signed-off-by: Sasha Levin

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 320

2019-06-05T15:37:05Z

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms and conditions of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 33 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Kate Stewart Reviewed-by: Alexios Zavras Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190530000435.254582722@linutronix.de Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Fix race condition with new ring_buffer_info mutex

2019-04-10T22:58:56Z

Fix a race condition that can result in a ring buffer pointer being set to null while a "_show" function is reading the ring buffer's data. This problem was discussed here: https://lkml.org/lkml/2018/10/18/779 To fix the race condition, add a new mutex lock to the "hv_ring_buffer_info" struct. Add a new function, "hv_ringbuffer_pre_init()", where a channel's inbound and outbound ring_buffer_info mutex locks are initialized. Acquire/release the locks in the "hv_ringbuffer_cleanup()" function, which is where the ring buffer pointers are set to null. Acquire/release the locks in the four channel-level "_show" functions that access ring buffer data. Remove the "const" qualifier from the "vmbus_channel" parameter and the "rbi" variable of the channel-level "_show" functions so that the locks can be acquired/released in these functions. Acquire/release the locks in hv_ringbuffer_get_debuginfo(). Remove the "const" qualifier from the "hv_ring_buffer_info" parameter so that the locks can be acquired/released in this function. Signed-off-by: Kimberly Brown Reviewed-by: Michael Kelley Signed-off-by: Sasha Levin

Drivers: hv: vmbus: Set ring_info field to 0 and remove memset

2019-04-10T22:58:56Z

Set "ring_info->priv_read_index" to 0. Now, all of ring_info's fields are explicitly set in this function. The memset() call is no longer necessary, so remove it. Signed-off-by: Kimberly Brown Reviewed-by: Michael Kelley Signed-off-by: Sasha Levin

Drivers: hv: vmbus: Expose counters for interrupts and full conditions

2019-02-15T01:56:10Z

Counter values for per-channel interrupts and ring buffer full conditions are useful for investigating performance. Expose counters in sysfs for 2 types of guest to host interrupts: 1) Interrupts caused by the channel's outbound ring buffer transitioning from empty to not empty 2) Interrupts caused by the channel's inbound ring buffer transitioning from full to not full while a packet is waiting for enough buffer space to become available Expose 2 counters in sysfs for the number of times that write operations encountered a full outbound ring buffer: 1) The total number of write operations that encountered a full condition 2) The number of write operations that were the first to encounter a full condition Increment the outbound full condition counters in the hv_ringbuffer_write() function because, for most drivers, a full outbound ring buffer is detected in that function. Also increment the outbound full condition counters in the set_channel_pending_send_size() function. In the hv_sock driver, a full outbound ring buffer is detected and set_channel_pending_send_size() is called before hv_ringbuffer_write() is called. I tested this patch by confirming that the sysfs files were created and observing the counter values. The values seemed to increase by a reasonable amount when the Hyper-v related drivers were in use. Signed-off-by: Kimberly Brown Reviewed-by: Michael Kelley Signed-off-by: Sasha Levin