and there is this missing part in patches in https://lore.kernel.org/qemu-devel/20240222222218.2261956-1-gustavo.rom...@linaro.org/ missing property for ivshmem-flat "x-bus-qompath" which is present in https://lore.kernel.org/qemu-devel/20231127052024.435743-2-gustavo.rom...@linaro.org/ patches.
without that prop, -chardev socket,path=/tmp/ivshmem_socket,id=ivshmem_flat -device ivshmem-flat,chardev=ivshmem_flat,x-irq-qompath='/machine/unattached/device[4]/gic/unnamed-gpio-in[0]',x-bus-qompath='/sysbus' isn't working. On Thu, May 16, 2024 at 2:52 PM Sanjeev Kumar <reachsanje...@gmail.com> wrote: > Hi Philippe, > I have taken patches from the link you provided > and built QEMU and started appending below line to QEMU > > -chardev socket,path=/tmp/ivshmem_socket,id=ivshmem_flat -device > ivshmem-flat,chardev=ivshmem_flat,x-irq-qompath='/machine/unattached/device[4]/gic/unnamed-gpio-in[0]',x-bus-qompath='/sysbus' > > and QEMU boots without any error > > I would like to get some help regarding data writing and reading from > shared memory. > > when using ivshmem-plain, i used to write data from host like > echo "hello" > /dev/shm/shm1 and in guest i was reading from pci bus BAR > and i was able to get data. > > similarly can you please help me with ivshmem-flat like where is the > location to write/read the data from host and in guest. > > Thanks & Regards, > Sanjeev. > > On Tue, May 14, 2024 at 9:56 PM Philippe Mathieu-Daudé <phi...@linaro.org> > wrote: > >> On 14/5/24 12:23, Sanjeev Kumar wrote: >> > and forgot to mention. why our VM doesn't support ivshmem because it >> > doesn't have PCI supported. >> > Is there any other shared memory mechanism QEMU which doesn't use the >> > PCI interface? >> > >> > On Tue, May 14, 2024 at 11:28 AM Sanjeev Kumar <reachsanje...@gmail.com >> > <mailto:reachsanje...@gmail.com>> wrote: >> > >> > Hi, >> > is there any other mechanism of shared memory with QEMU other than >> > ivshmem? >> > I tried ivshmem with ubuntu vm with qemu x86_64 and it is working >> > fine. but our use case is with ARM and ivshmem isn't supported by >> > our custom VM. so please let me know if we have any other mechanism >> > other than ivshmem. >> >> Hi Sanjeev, >> >> You might be interested by Gustavo approach (he provided some >> examples): >> >> https://lore.kernel.org/qemu-devel/20240222222218.2261956-1-gustavo.rom...@linaro.org/ >> >> Regards, >> >> Phil. >> >
