similar to: [PATCH 2/4] virtio: console: Fix early_put_chars usage

Hi all, As far as I can see, early_put_chars is not used by virtio_console because it checks whether there is a port available before using it. If I understand correctly, this makes it useless because once we have a port, we can use the regular virtio transport to output things to the console. Does the attached patch seem valid ? Feedback from s390 and powerpc users who use this functionality

Hi all, As far as I can see, early_put_chars is not used by virtio_console because it checks whether there is a port available before using it. If I understand correctly, this makes it useless because once we have a port, we can use the regular virtio transport to output things to the console. Does the attached patch seem valid ? Feedback from s390 and powerpc users who use this functionality

Hey Rusty, These updated patches in the series return -EFAULT on copy_xx_user errors and also move the copy_from_user into fops_write() instead of it being in send_buf. This enables send_buf to just read from kernel buffers, making it simpler. This also allows write()s to write more to the host in one go, removingthe 4k limitation. I do limit the writes to 32k at once to not put too much

Hey Rusty, These updated patches in the series return -EFAULT on copy_xx_user errors and also move the copy_from_user into fops_write() instead of it being in send_buf. This enables send_buf to just read from kernel buffers, making it simpler. This also allows write()s to write more to the host in one go, removingthe 4k limitation. I do limit the writes to 32k at once to not put too much

From: Omar Sandoval <osandov at fb.com> put_chars() stuffs the buffer it gets into an sg, but that buffer may be on the stack. This breaks with CONFIG_VMAP_STACK=y (for me, it manifested as printks getting turned into NUL bytes). Signed-off-by: Omar Sandoval <osandov at fb.com> --- Patch based on v4.10-rc6. drivers/char/virtio_console.c | 12 ++++++++++-- 1 file changed, 10

From: Omar Sandoval <osandov at fb.com> put_chars() stuffs the buffer it gets into an sg, but that buffer may be on the stack. This breaks with CONFIG_VMAP_STACK=y (for me, it manifested as printks getting turned into NUL bytes). Signed-off-by: Omar Sandoval <osandov at fb.com> --- Patch based on v4.10-rc6. drivers/char/virtio_console.c | 12 ++++++++++-- 1 file changed, 10

Expose multiple char devices ("ports") for simple communication between the host userspace and guest. Sample offline usages can be: poking around in a guest to find out the file systems used, applications installed, etc. Online usages can be sharing of clipboard data between the guest and the host, sending information about logged-in users to the host, locking the screen or session when

Expose multiple char devices ("ports") for simple communication between the host userspace and guest. Sample offline usages can be: poking around in a guest to find out the file systems used, applications installed, etc. Online usages can be sharing of clipboard data between the guest and the host, sending information about logged-in users to the host, locking the screen or session when

From: Christian Borntraeger <borntraeger at de.ibm.com> In case the registration of the hvc tty never happens AND the kernel thinks that hvc0 is the preferred console we should keep the early printk function to avoid a kernel panic due to code being removed. Signed-off-by: Christian Borntraeger <borntraeger at de.ibm.com> Signed-off-by: Jing Liu <liujbjl at linux.vnet.ibm.com>

The following changes since commit 48de8cb7847d040c8892701c1ff3c55eff1f46b4: Linus Torvalds (1): Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/.../tip/linux-2.6-tip are available in the git repository at: ssh://master.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus.git master Amit Shah (1): MAINTAINERS: Put the virtio-console entry in

The following changes since commit 48de8cb7847d040c8892701c1ff3c55eff1f46b4: Linus Torvalds (1): Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/.../tip/linux-2.6-tip are available in the git repository at: ssh://master.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus.git master Amit Shah (1): MAINTAINERS: Put the virtio-console entry in

A bug can be easily reproduced: Host# cat guest-agent.xml <channel type="unix"> <source mode="bind" path="/var/lib/libvirt/qemu/stretch.agent"/> <target type="virtio" name="org.qemu.guest_agent.0" state="connected"/> </channel> Host# virsh attach-device instance guest-agent.xml Host# virsh detach-device

On Sun, Apr 28, 2019 at 09:50:04AM +0800, zhenwei pi wrote: > A bug can be easily reproduced: > Host# cat guest-agent.xml > <channel type="unix"> > <source mode="bind" path="/var/lib/libvirt/qemu/stretch.agent"/> > <target type="virtio" name="org.qemu.guest_agent.0" state="connected"/> >

A bug can be easily reproduced: Host# cat guest-agent.xml <channel type="unix"> <source mode="bind" path="/var/lib/libvirt/qemu/stretch.agent"/> <target type="virtio" name="org.qemu.guest_agent.0" state="connected"/> </channel> Host# virsh attach-device instance guest-agent.xml Host# virsh detach-device

A bug can be easily reproduced: Host# cat guest-agent.xml <channel type="unix"> <source mode="bind" path="/var/lib/libvirt/qemu/stretch.agent"/> <target type="virtio" name="org.qemu.guest_agent.0" state="connected"/> </channel> Host# virsh attach-device instance guest-agent.xml Host# virsh detach-device

Hey Rusty, In this version: - Assume only one inbuf; no input buffering for ports - Remove the START/END delimiters for outgoing buffers - Remove the header that was sent along with each buffer - Remove unused buffers in the vqs at port remove time - Send a guest port open message to the host when a console port is attached - Remove cached buffers when ports are closed / disconnected - Send

Hey Rusty, In this version: - Assume only one inbuf; no input buffering for ports - Remove the START/END delimiters for outgoing buffers - Remove the header that was sent along with each buffer - Remove unused buffers in the vqs at port remove time - Send a guest port open message to the host when a console port is attached - Remove cached buffers when ports are closed / disconnected - Send

Hey Rusty, Christian, Christoph Hellwig asked why we don't need a barrier before this code in virtcons_probe(): > + /* Start using the new console output. */ > + early_put_chars = NULL; > return 0; Since only s390 uses early_put_chars so far, you'd know why it's not needed / why we're safe. Thanks, Amit

Hey Rusty, Christian, Christoph Hellwig asked why we don't need a barrier before this code in virtcons_probe(): > + /* Start using the new console output. */ > + early_put_chars = NULL; > return 0; Since only s390 uses early_put_chars so far, you'd know why it's not needed / why we're safe. Thanks, Amit

Unfortunately there proved to be at least one bug which requires an ABI change, so we're best off not introducing multiport support until 2.6.35. While I generally left the multiport code paths intact, I really wanted to remove the ABI defines from the header, which meant some quite deep cuts. Signed-off-by: Rusty Russell <rusty at rustcorp.com.au> To: Amit Shah <amit.shah at