KVM: PPC: Book3S HV P9: Optimise hash guest SLB saving
authorNicholas Piggin <npiggin@gmail.com>
Tue, 23 Nov 2021 09:52:24 +0000 (19:52 +1000)
committerMichael Ellerman <mpe@ellerman.id.au>
Wed, 24 Nov 2021 10:09:02 +0000 (21:09 +1100)
commit241d1f19f0e5c257881a0661f201b51dc3e57f8c
tree5d63136f9c86a397037e13b55ccf2837267e6593
parentb49c65c5f9f1dac4ef1764578ad55bacf526eb38
KVM: PPC: Book3S HV P9: Optimise hash guest SLB saving

slbmfee/slbmfev instructions are very expensive, moreso than a regular
mfspr instruction, so minimising them significantly improves hash guest
exit performance. The slbmfev is only required if slbmfee found a valid
SLB entry.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211123095231.1036501-47-npiggin@gmail.com
arch/powerpc/kvm/book3s_hv_p9_entry.c