arm64: KVM: VHE: Implement VHE activate/deactivate_traps
Running the kernel in HYP mode requires the HCR_E2H bit to be set
at all times, and the HCR_TGE bit to be set when running as a host
(and cleared when running as a guest). At the same time, the vector
must be set to the current role of the kernel (either host or
hypervisor), and a couple of system registers differ between VHE
and non-VHE.
We implement these by using another set of alternate functions
that get dynamically patched.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index 0d82ae9..e609942 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -15,6 +15,8 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#include <asm/kvm_asm.h>
+
#include "hyp.h"
static bool __hyp_text __fpsimd_enabled_nvhe(void)
@@ -36,6 +38,31 @@
return __fpsimd_is_enabled()();
}
+static void __hyp_text __activate_traps_vhe(void)
+{
+ u64 val;
+
+ val = read_sysreg(cpacr_el1);
+ val |= CPACR_EL1_TTA;
+ val &= ~CPACR_EL1_FPEN;
+ write_sysreg(val, cpacr_el1);
+
+ write_sysreg(__kvm_hyp_vector, vbar_el1);
+}
+
+static void __hyp_text __activate_traps_nvhe(void)
+{
+ u64 val;
+
+ val = CPTR_EL2_DEFAULT;
+ val |= CPTR_EL2_TTA | CPTR_EL2_TFP;
+ write_sysreg(val, cptr_el2);
+}
+
+static hyp_alternate_select(__activate_traps_arch,
+ __activate_traps_nvhe, __activate_traps_vhe,
+ ARM64_HAS_VIRT_HOST_EXTN);
+
static void __hyp_text __activate_traps(struct kvm_vcpu *vcpu)
{
u64 val;
@@ -55,20 +82,34 @@
write_sysreg(val, hcr_el2);
/* Trap on AArch32 cp15 c15 accesses (EL1 or EL0) */
write_sysreg(1 << 15, hstr_el2);
-
- val = CPTR_EL2_DEFAULT;
- val |= CPTR_EL2_TTA | CPTR_EL2_TFP;
- write_sysreg(val, cptr_el2);
-
write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2);
+ __activate_traps_arch()();
}
+static void __hyp_text __deactivate_traps_vhe(void)
+{
+ extern char vectors[]; /* kernel exception vectors */
+
+ write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2);
+ write_sysreg(CPACR_EL1_FPEN, cpacr_el1);
+ write_sysreg(vectors, vbar_el1);
+}
+
+static void __hyp_text __deactivate_traps_nvhe(void)
+{
+ write_sysreg(HCR_RW, hcr_el2);
+ write_sysreg(CPTR_EL2_DEFAULT, cptr_el2);
+}
+
+static hyp_alternate_select(__deactivate_traps_arch,
+ __deactivate_traps_nvhe, __deactivate_traps_vhe,
+ ARM64_HAS_VIRT_HOST_EXTN);
+
static void __hyp_text __deactivate_traps(struct kvm_vcpu *vcpu)
{
- write_sysreg(HCR_RW, hcr_el2);
+ __deactivate_traps_arch()();
write_sysreg(0, hstr_el2);
write_sysreg(read_sysreg(mdcr_el2) & MDCR_EL2_HPMN_MASK, mdcr_el2);
- write_sysreg(CPTR_EL2_DEFAULT, cptr_el2);
}
static void __hyp_text __activate_vm(struct kvm_vcpu *vcpu)