[PATCH v2 14/21] arm64: KVM: VHE: Implement VHE activate/deactivate_traps
From: Marc Zyngier <hidden>
Date: 2016-01-25 16:01:58
Also in:
kvm, kvmarm, lkml
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
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. Signed-off-by: Marc Zyngier <redacted> --- arch/arm64/include/asm/kvm_arm.h | 1 + arch/arm64/include/asm/kvm_emulate.h | 3 +++ arch/arm64/kvm/hyp/switch.c | 52 +++++++++++++++++++++++++++++++++--- 3 files changed, 53 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 738a95f..73d3826 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h@@ -23,6 +23,7 @@ #include <asm/types.h> /* Hyp Configuration Register (HCR) bits */ +#define HCR_E2H (UL(1) << 34) #define HCR_ID (UL(1) << 33) #define HCR_CD (UL(1) << 32) #define HCR_RW_SHIFT 31
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index 3066328..5ae0c69 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h@@ -29,6 +29,7 @@ #include <asm/kvm_mmio.h> #include <asm/ptrace.h> #include <asm/cputype.h> +#include <asm/virt.h> unsigned long *vcpu_reg32(const struct kvm_vcpu *vcpu, u8 reg_num); unsigned long *vcpu_spsr32(const struct kvm_vcpu *vcpu);
@@ -43,6 +44,8 @@ void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr); static inline void vcpu_reset_hcr(struct kvm_vcpu *vcpu) { vcpu->arch.hcr_el2 = HCR_GUEST_FLAGS; + if (is_kernel_in_hyp_mode()) + vcpu->arch.hcr_el2 |= HCR_E2H; if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) vcpu->arch.hcr_el2 &= ~HCR_RW; }
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index 6f264dc..77f7c94 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 +38,27 @@ 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 |= 1 << 28; + val &= ~(3 << 20); + write_sysreg(val, cpacr_el1); + + write_sysreg(__kvm_hyp_vector, vbar_el1); +} + +static void __hyp_text __activate_traps_nvhe(void) +{ + write_sysreg(CPTR_EL2_TTA | CPTR_EL2_TFP, 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;
@@ -55,16 +78,39 @@ 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); - write_sysreg(CPTR_EL2_TTA | CPTR_EL2_TFP, cptr_el2); write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2); + __activate_traps_arch()(); } -static void __hyp_text __deactivate_traps(struct kvm_vcpu *vcpu) +static void __hyp_text __deactivate_traps_vhe(void) +{ + extern char vectors[]; /* kernel exception vectors */ + u64 val; + + write_sysreg(HCR_RW | HCR_TGE | HCR_E2H, hcr_el2); + + val = read_sysreg(cpacr_el1); + val |= 3 << 20; + write_sysreg(val, cpacr_el1); + + write_sysreg(vectors, vbar_el1); +} + +static void __hyp_text __deactivate_traps_nvhe(void) { write_sysreg(HCR_RW, hcr_el2); + write_sysreg(0, 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) +{ + __deactivate_traps_arch()(); write_sysreg(0, hstr_el2); write_sysreg(read_sysreg(mdcr_el2) & MDCR_EL2_HPMN_MASK, mdcr_el2); - write_sysreg(0, cptr_el2); } static void __hyp_text __activate_vm(struct kvm_vcpu *vcpu)
--
2.1.4