diff options
| -rw-r--r-- | arch/arm/include/asm/kvm_host.h | 1 | ||||
| -rw-r--r-- | arch/arm64/Kconfig | 7 | ||||
| -rw-r--r-- | arch/arm64/include/asm/kvm_host.h | 13 | ||||
| -rw-r--r-- | arch/arm64/kvm/fpsimd.c | 1 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/switch.c | 20 | ||||
| -rw-r--r-- | virt/kvm/arm/arm.c | 7 |
6 files changed, 47 insertions, 2 deletions
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index ac870b2cd5d1..3b85bbb4b23e 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -280,6 +280,7 @@ void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot); struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr); +static inline bool kvm_arch_check_sve_has_vhe(void) { return true; } static inline void kvm_arch_hardware_unsetup(void) {} static inline void kvm_arch_sync_events(struct kvm *kvm) {} static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {} diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index eb2cf4938f6d..b0d3820081c8 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1130,6 +1130,7 @@ 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 @@ -1155,6 +1156,12 @@ 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 select HAVE_MOD_ARCH_SPECIFIC diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index b3fe7301bdbe..fda9289f3b9c 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -405,6 +405,19 @@ static inline void __cpu_init_hyp_mode(phys_addr_t pgd_ptr, kvm_call_hyp(__kvm_set_tpidr_el2, tpidr_el2); } +static inline bool kvm_arch_check_sve_has_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 has_vhe(); + else + return true; +} + static inline void kvm_arch_hardware_unsetup(void) {} static inline void kvm_arch_sync_events(struct kvm *kvm) {} static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {} diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c index 365933a98a7c..dc6ecfa5a2d2 100644 --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -59,7 +59,6 @@ error: */ void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu) { - BUG_ON(system_supports_sve()); BUG_ON(!current->mm); vcpu->arch.flags &= ~(KVM_ARM64_FP_ENABLED | KVM_ARM64_HOST_SVE_IN_USE); diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index 118f3002b9ce..a6a8c7d9157d 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -21,6 +21,7 @@ #include <kvm/arm_psci.h> +#include <asm/cpufeature.h> #include <asm/kvm_asm.h> #include <asm/kvm_emulate.h> #include <asm/kvm_host.h> @@ -28,6 +29,7 @@ #include <asm/kvm_mmu.h> #include <asm/fpsimd.h> #include <asm/debug-monitors.h> +#include <asm/processor.h> #include <asm/thread_info.h> /* Check whether the FP regs were dirtied while in the host-side run loop: */ @@ -329,6 +331,8 @@ static bool __hyp_text __skip_instr(struct kvm_vcpu *vcpu) void __hyp_text __hyp_switch_fpsimd(u64 esr __always_unused, struct kvm_vcpu *vcpu) { + struct user_fpsimd_state *host_fpsimd = vcpu->arch.host_fpsimd_state; + if (has_vhe()) write_sysreg(read_sysreg(cpacr_el1) | CPACR_EL1_FPEN, cpacr_el1); @@ -339,7 +343,21 @@ void __hyp_text __hyp_switch_fpsimd(u64 esr __always_unused, isb(); if (vcpu->arch.flags & KVM_ARM64_FP_HOST) { - __fpsimd_save_state(vcpu->arch.host_fpsimd_state); + /* + * In the SVE case, VHE is assumed: it is enforced by + * Kconfig and kvm_arch_init(). + */ + if (system_supports_sve() && + (vcpu->arch.flags & KVM_ARM64_HOST_SVE_IN_USE)) { + struct thread_struct *thread = container_of( + host_fpsimd, + struct thread_struct, uw.fpsimd_state); + + sve_save_state(sve_pffr(thread), &host_fpsimd->fpsr); + } else { + __fpsimd_save_state(host_fpsimd); + } + vcpu->arch.flags &= ~KVM_ARM64_FP_HOST; } diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index bee226cec40b..ce7c6f36471b 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -16,6 +16,7 @@ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ +#include <linux/bug.h> #include <linux/cpu_pm.h> #include <linux/errno.h> #include <linux/err.h> @@ -41,6 +42,7 @@ #include <asm/mman.h> #include <asm/tlbflush.h> #include <asm/cacheflush.h> +#include <asm/cpufeature.h> #include <asm/virt.h> #include <asm/kvm_arm.h> #include <asm/kvm_asm.h> @@ -1574,6 +1576,11 @@ int kvm_arch_init(void *opaque) return -ENODEV; } + if (!kvm_arch_check_sve_has_vhe()) { + kvm_pr_unimpl("SVE system without VHE unsupported. Broken cpu?"); + return -ENODEV; + } + for_each_online_cpu(cpu) { smp_call_function_single(cpu, check_kvm_target_cpu, &ret, 1); if (ret < 0) { |