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arm64: KVM: VHE: Implement VHE activate/deactivate_traps

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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>
This commit is contained in:
Marc Zyngier
2015-01-29 15:47:55 +00:00
parent 328762247c
commit 68908bf789
3 changed files with 53 additions and 8 deletions
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55
arch/arm64/kvm/hyp/switch.c
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@@ -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 @@ bool __hyp_text __fpsimd_enabled(void)
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 @@ static void __hyp_text __activate_traps(struct kvm_vcpu *vcpu)
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)