]> git.baikalelectronics.ru Git - kernel.git/commit
KVM: PPC: Book3S HV P9: implement hash guest support
authorNicholas Piggin <npiggin@gmail.com>
Fri, 28 May 2021 09:07:50 +0000 (19:07 +1000)
committerMichael Ellerman <mpe@ellerman.id.au>
Thu, 10 Jun 2021 12:12:15 +0000 (22:12 +1000)
commit8fbfc2d786a0e8d16cb475641b24703dd60697c5
tree33bc987d0937d93d98f56733084e2a1fce5081c0
parentc8300db3207d983bda886320bd706e8da2558b24
KVM: PPC: Book3S HV P9: implement hash guest support

Implement hash guest support. Guest entry/exit has to restore and
save/clear the SLB, plus several other bits to accommodate hash guests
in the P9 path. Radix host, hash guest support is removed from the P7/8
path.

The HPT hcalls and faults are not handled in real mode, which is a
performance regression. A worst-case fork/exit microbenchmark takes 3x
longer after this patch. kbuild benchmark performance is in the noise,
but the slowdown is likely to be noticed somewhere.

For now, accept this penalty for the benefit of simplifying the P7/8
paths and unifying P9 hash with the new code, because hash is a less
important configuration than radix on processors that support it. Hash
will benefit from future optimisations to this path, including possibly
a faster path to handle such hcalls and interrupts without doing a full
exit.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-31-npiggin@gmail.com
arch/powerpc/include/asm/kvm_asm.h
arch/powerpc/kvm/book3s_64_entry.S
arch/powerpc/kvm/book3s_hv.c
arch/powerpc/kvm/book3s_hv_p9_entry.c
arch/powerpc/kvm/book3s_hv_rm_mmu.c
arch/powerpc/kvm/book3s_hv_rmhandlers.S