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Groups > linux.kernel > #1316932
| From | Marc Zyngier <marc.zyngier@arm.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH v2 14/21] arm64: KVM: VHE: Implement VHE activate/deactivate_traps |
| Date | 2016-01-25 17:10 +0100 |
| Message-ID | <qURSl-6uy-71@gated-at.bofh.it> (permalink) |
| References | <qURIC-68y-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
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 <marc.zyngier@arm.com>
---
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
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[PATCH v2 00/21] arm64: Virtualization Host Extension support Marc Zyngier <marc.zyngier@arm.com> - 2016-01-25 17:00 +0100
[PATCH v2 16/21] arm64: KVM: VHE: Add fpsimd enabling on guest access Marc Zyngier <marc.zyngier@arm.com> - 2016-01-25 17:00 +0100
[PATCH v2 09/21] arm64: KVM: VHE: Differenciate host/guest sysreg save/restore Marc Zyngier <marc.zyngier@arm.com> - 2016-01-25 17:00 +0100
[PATCH v2 06/21] arm64: KVM: VHE: Patch out use of HVC Marc Zyngier <marc.zyngier@arm.com> - 2016-01-25 17:00 +0100
[PATCH v2 15/21] arm64: KVM: VHE: Use unified sysreg accessors for timer Marc Zyngier <marc.zyngier@arm.com> - 2016-01-25 17:00 +0100
[PATCH v2 21/21] arm64: Panic when VHE and non VHE CPUs coexist Marc Zyngier <marc.zyngier@arm.com> - 2016-01-25 17:00 +0100
Re: [PATCH v2 21/21] arm64: Panic when VHE and non VHE CPUs coexist "Suzuki K. Poulose" <Suzuki.Poulose@arm.com> - 2016-01-26 15:30 +0100
Re: [PATCH v2 21/21] arm64: Panic when VHE and non VHE CPUs coexist Marc Zyngier <marc.zyngier@arm.com> - 2016-01-26 15:40 +0100
[PATCH v2 10/21] arm64: KVM: VHE: Split save/restore of sysregs shared between EL1 and EL2 Marc Zyngier <marc.zyngier@arm.com> - 2016-01-25 17:00 +0100
[PATCH v2 20/21] arm64: VHE: Add support for running Linux in EL2 mode Marc Zyngier <marc.zyngier@arm.com> - 2016-01-25 17:00 +0100
Re: [PATCH v2 20/21] arm64: VHE: Add support for running Linux in EL2 mode "Suzuki K. Poulose" <Suzuki.Poulose@arm.com> - 2016-01-26 15:10 +0100
Re: [PATCH v2 20/21] arm64: VHE: Add support for running Linux in EL2 mode "Suzuki K. Poulose" <Suzuki.Poulose@arm.com> - 2016-01-26 15:40 +0100
[PATCH v2 17/21] arm64: KVM: VHE: Add alternative panic handling Marc Zyngier <marc.zyngier@arm.com> - 2016-01-25 17:00 +0100
[PATCH v2 05/21] arm64: KVM: VHE: Turn VTCR_EL2 setup into a reusable macro Marc Zyngier <marc.zyngier@arm.com> - 2016-01-25 17:00 +0100
[PATCH v2 11/21] arm64: KVM: VHE: Use unified system register accessors Marc Zyngier <marc.zyngier@arm.com> - 2016-01-25 17:10 +0100
[PATCH v2 03/21] arm64: Add ARM64_HAS_VIRT_HOST_EXTN feature Marc Zyngier <marc.zyngier@arm.com> - 2016-01-25 17:10 +0100
[PATCH v2 08/21] arm64: KVM: VHE: Introduce unified system register accessors Marc Zyngier <marc.zyngier@arm.com> - 2016-01-25 17:10 +0100
[PATCH v2 04/21] arm64: KVM: Skip HYP setup when already running in HYP Marc Zyngier <marc.zyngier@arm.com> - 2016-01-25 17:10 +0100
[PATCH v2 02/21] arm64: Allow the arch timer to use the HYP timer Marc Zyngier <marc.zyngier@arm.com> - 2016-01-25 17:10 +0100
[PATCH v2 13/21] arm64: KVM: VHE: Make __fpsimd_enabled VHE aware Marc Zyngier <marc.zyngier@arm.com> - 2016-01-25 17:10 +0100
[PATCH v2 14/21] arm64: KVM: VHE: Implement VHE activate/deactivate_traps Marc Zyngier <marc.zyngier@arm.com> - 2016-01-25 17:10 +0100
[PATCH v2 07/21] arm64: KVM: VHE: Patch out kern_hyp_va Marc Zyngier <marc.zyngier@arm.com> - 2016-01-25 17:10 +0100
Re: [PATCH v2 00/21] arm64: Virtualization Host Extension support Arnd Bergmann <arnd@arndb.de> - 2016-01-25 17:20 +0100
Re: [PATCH v2 00/21] arm64: Virtualization Host Extension support Arnd Bergmann <arnd@arndb.de> - 2016-01-25 17:30 +0100
Re: [PATCH v2 00/21] arm64: Virtualization Host Extension support Marc Zyngier <marc.zyngier@arm.com> - 2016-01-25 17:30 +0100
Re: [PATCH v2 00/21] arm64: Virtualization Host Extension support Will Deacon <will.deacon@arm.com> - 2016-01-25 17:30 +0100
Re: [PATCH v2 00/21] arm64: Virtualization Host Extension support Marc Zyngier <marc.zyngier@arm.com> - 2016-01-25 17:40 +0100
Re: [PATCH v2 00/21] arm64: Virtualization Host Extension support Will Deacon <will.deacon@arm.com> - 2016-01-25 17:50 +0100
Re: [PATCH v2 00/21] arm64: Virtualization Host Extension support Marc Zyngier <marc.zyngier@arm.com> - 2016-01-25 20:20 +0100
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