diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2020-07-26 06:51:55 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-07-29 14:02:10 +0300 |
| commit | 107c55005fbd5243ee31fb13b6f166cde9e3ade1 (patch) | |
| tree | 568f339e22efacf3f857e8ed04e926e9a97f2bf5 /arch/powerpc/include/asm/firmware.h | |
| parent | 5b06d1679f2fe874ef49ea11324cd893ec9e2da8 (diff) | |
| download | linux-107c55005fbd5243ee31fb13b6f166cde9e3ade1.tar.xz | |
powerpc/pseries: Add KVM guest doorbell restrictions
KVM guests have certain restrictions and performance quirks when using
doorbells. This patch moves the EPAPR KVM guest test so it can be shared
with PSERIES, and uses that in doorbell setup code to apply the KVM
guest quirks and improves IPI performance for two cases:
- PowerVM guests may now use doorbells even if they are secure.
- KVM guests no longer use doorbells if XIVE is available.
There is a valid complaint that "KVM guest" is not a very reasonable
thing to test for, it's preferable for the hypervisor to advertise
particular behaviours to the guest so they could change if the
hypervisor implementation or configuration changes. However in this case
we were already assuming a KVM guest worst case, so this patch is about
containing those quirks. If KVM later advertises fast doorbells, we
should test for that and override the quirks.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200726035155.1424103-4-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/include/asm/firmware.h')
| -rw-r--r-- | arch/powerpc/include/asm/firmware.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/firmware.h b/arch/powerpc/include/asm/firmware.h index 6003c2e533a0..f67efbaba17f 100644 --- a/arch/powerpc/include/asm/firmware.h +++ b/arch/powerpc/include/asm/firmware.h @@ -132,6 +132,12 @@ extern int ibm_nmi_interlock_token; extern unsigned int __start___fw_ftr_fixup, __stop___fw_ftr_fixup; +#if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_KVM_GUEST) +bool is_kvm_guest(void); +#else +static inline bool is_kvm_guest(void) { return false; } +#endif + #ifdef CONFIG_PPC_PSERIES void pseries_probe_fw_features(void); #else |