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authorDave Martin <Dave.Martin@arm.com>2018-04-20 16:20:43 +0100
committerMarc Zyngier <marc.zyngier@arm.com>2018-05-25 12:28:29 +0100
commit85acda3b4a27ee3e20c54783a44f307b51912c2b (patch)
tree0a2f7213311009b9a244cb5d6bc862c14ce2a3cf /virt/kvm
parent9a6e594869b29ccec4f99db83c071e4f2dbfc11f (diff)
KVM: arm64: Save host SVE context as appropriate
This patch adds SVE context saving to the hyp FPSIMD context switch path. This means that it is no longer necessary to save the host SVE state in advance of entering the guest, when in use. In order to avoid adding pointless complexity to the code, VHE is assumed if SVE is in use. VHE is an architectural prerequisite for SVE, so there is no good reason to turn CONFIG_ARM64_VHE off in kernels that support both SVE and KVM. Historically, software models exist that can expose the architecturally invalid configuration of SVE without VHE, so if this situation is detected at kvm_init() time then KVM will be disabled. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'virt/kvm')
-rw-r--r--virt/kvm/arm/arm.c7
1 files changed, 7 insertions, 0 deletions
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) {