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| author |   Claudio Imbrenda <imbrenda@linux.ibm.com> | 2021-09-20 15:24:52 +0200 |
|---|---|---|
| committer |   Christian Borntraeger <borntraeger@de.ibm.com> | 2021-10-25 09:20:39 +0200 |
| commit | f0a1a0615a6ff6d38af2c65a522698fb4bb85df6 (patch) | |
| tree | 3e7603404c56abc27670b823b223c2e1d5435118 /drivers/fpga/fpga-mgr.c | |
| parent | KVM: s390: pv: avoid stalls for kvm_s390_pv_init_vm (diff) | |
| download | linux-dev-f0a1a0615a6ff6d38af2c65a522698fb4bb85df6.tar.xz linux-dev-f0a1a0615a6ff6d38af2c65a522698fb4bb85df6.zip | |
KVM: s390: pv: avoid stalls when making pages secure
Improve make_secure_pte to avoid stalls when the system is heavily
overcommitted. This was especially problematic in kvm_s390_pv_unpack,
because of the loop over all pages that needed unpacking.
Due to the locks being held, it was not possible to simply replace
uv_call with uv_call_sched. A more complex approach was
needed, in which uv_call is replaced with __uv_call, which does not
loop. When the UVC needs to be executed again, -EAGAIN is returned, and
the caller (or its caller) will try again.
When -EAGAIN is returned, the path is the same as when the page is in
writeback (and the writeback check is also performed, which is
harmless).
Fixes: 214d9bbcd3a672 ("s390/mm: provide memory management functions for protected KVM guests")
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Link: https://lore.kernel.org/r/20210920132502.36111-5-imbrenda@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Diffstat (limited to 'drivers/fpga/fpga-mgr.c')
0 files changed, 0 insertions, 0 deletions