From d06b76be8dad2e2fa62f68264887cc295d67a3ef Mon Sep 17 00:00:00 2001 From: Dave Martin Date: Fri, 28 Sep 2018 14:39:10 +0100 Subject: arm64/sve: Check SVE virtualisability Due to the way the effective SVE vector length is controlled and trapped at different exception levels, certain mismatches in the sets of vector lengths supported by different physical CPUs in the system may prevent straightforward virtualisation of SVE at parity with the host. This patch analyses the extent to which SVE can be virtualised safely without interfering with migration of vcpus between physical CPUs, and rejects late secondary CPUs that would erode the situation further. It is left up to KVM to decide what to do with this information. Signed-off-by: Dave Martin Reviewed-by: Julien Thierry Tested-by: zhang.lei Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/fpsimd.h | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/arm64/include') diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h index dd1ad3950ef5..964adc9f312d 100644 --- a/arch/arm64/include/asm/fpsimd.h +++ b/arch/arm64/include/asm/fpsimd.h @@ -87,6 +87,7 @@ extern void sve_kernel_enable(const struct arm64_cpu_capabilities *__unused); extern u64 read_zcr_features(void); extern int __ro_after_init sve_max_vl; +extern int __ro_after_init sve_max_virtualisable_vl; #ifdef CONFIG_ARM64_SVE -- cgit v1.2.3