Commit 6e94095c authored by Daniel Kiss's avatar Daniel Kiss Committed by Marc Zyngier
Browse files

KVM: arm64: Enable SVE support for nVHE 



Now that KVM is equipped to deal with SVE on nVHE, remove the code
preventing it from being used as well as the bits of documentation
that were mentioning the incompatibility.

Acked-by: default avatarWill Deacon <will@kernel.org>
Signed-off-by: default avatarDaniel Kiss <daniel.kiss@arm.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent 8c8010d6

arch/arm64/Kconfig

+0 −7
Original line number Diff line number Diff line
@@ -1686,7 +1686,6 @@ endmenu 
config ARM64_SVE

	bool "ARM Scalable Vector Extension support"

	default y

	depends on !KVM || ARM64_VHE

	help

	  The Scalable Vector Extension (SVE) is an extension to the AArch64

	  execution state which complements and extends the SIMD functionality
@@ -1715,12 +1714,6 @@ config ARM64_SVE 
	  booting the kernel.  If unsure and you are not observing these

	  symptoms, you should assume that it is safe to say Y.



	  CPUs that support SVE are architecturally required to support the

	  Virtualization Host Extensions (VHE), so the kernel makes no

	  provision for supporting SVE alongside KVM without VHE enabled.

	  Thus, you will need to enable CONFIG_ARM64_VHE if you want to support

	  KVM in the same kernel image.



config ARM64_MODULE_PLTS

	bool "Use PLTs to allow module memory to spill over into vmalloc area"

	depends on MODULES

arch/arm64/include/asm/kvm_host.h

+0 −13
Original line number Diff line number Diff line
@@ -694,19 +694,6 @@ static inline void kvm_init_host_cpu_context(struct kvm_cpu_context *cpu_ctxt) 
	ctxt_sys_reg(cpu_ctxt, MPIDR_EL1) = read_cpuid_mpidr();

}



static inline bool kvm_arch_requires_vhe(void)

{

	/*

	 * The Arm architecture specifies that implementation of SVE

	 * requires VHE also to be implemented.  The KVM code for arm64

	 * relies on this when SVE is present:

	 */

	if (system_supports_sve())

		return true;



	return false;

}



void kvm_arm_vcpu_ptrauth_trap(struct kvm_vcpu *vcpu);



static inline void kvm_arch_hardware_unsetup(void) {}

arch/arm64/kvm/arm.c

+0 −5
Original line number Diff line number Diff line
@@ -1889,11 +1889,6 @@ int kvm_arch_init(void *opaque) 


	in_hyp_mode = is_kernel_in_hyp_mode();



	if (!in_hyp_mode && kvm_arch_requires_vhe()) {

		kvm_pr_unimpl("CPU unsupported in non-VHE mode, not initializing\n");

		return -ENODEV;

	}



	if (cpus_have_final_cap(ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE) ||

	    cpus_have_final_cap(ARM64_WORKAROUND_1508412))

		kvm_info("Guests without required CPU erratum workarounds can deadlock system!\n" \

arch/arm64/kvm/reset.c

+0 −4
Original line number Diff line number Diff line
@@ -74,10 +74,6 @@ static int kvm_vcpu_enable_sve(struct kvm_vcpu *vcpu) 
	if (!system_supports_sve())

		return -EINVAL;



	/* Verify that KVM startup enforced this when SVE was detected: */

	if (WARN_ON(!has_vhe()))

		return -EINVAL;



	vcpu->arch.sve_max_vl = kvm_sve_max_vl;



	/*