Re: [PATCH v7 00/14] KVM: mm: fd-based approach for supporting KVM guest private memory

On 11/08/22 19:02, Chao Peng wrote:

On Thu, Aug 11, 2022 at 01:30:06PM +0200, Gupta, Pankaj wrote:

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Test
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To test the new functionalities of this patch TDX patchset is needed.
Since TDX patchset has not been merged so I did two kinds of test:

-  Regresion test on kvm/queue (this patchset)
    Most new code are not covered. Code also in below repo:
    https://github.com/chao-p/linux/tree/privmem-v7

-  New Funational test on latest TDX code
    The patch is rebased to latest TDX code and tested the new
    funcationalities. See below repos:
    Linux: https://github.com/chao-p/linux/tree/privmem-v7-tdx
    QEMU: https://github.com/chao-p/qemu/tree/privmem-v7

While debugging an issue with SEV+UPM, found that fallocate() returns
an error in QEMU which is not handled (EINTR). With the below handling
of EINTR subsequent fallocate() succeeds:

QEMU code has not well-tested so it's not strange you met problem. But
from the man page, there is signal was caught for EINTR, do you know
the signal number?

I haven't check that, but that should be fairly straight forward to get.
I presume that you are referring to signal_pending() in the shmem_fallocate()

Thanks for you patch but before we change it in QEMU I want to make sure
it's indeed a QEMU issue (e.g. not a kernel isssue).

As per the manual fallocate() can return EINTR, and this should be handled 
by the user space.

Regards
Nikunj