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authorDavid Brazdil <dbrazdil@google.com>2020-12-02 21:41:21 +0300
committerMarc Zyngier <maz@kernel.org>2020-12-04 13:08:36 +0300
commitb93c17c4185bf6b50f2f0b332afb4abe8b766a7a (patch)
tree80d2c8db84a6814f364ef9d785e4a413237e2773
parentfa8c3d65538aa11bb117cbf872400d5caa7f340b (diff)
downloadlinux-b93c17c4185bf6b50f2f0b332afb4abe8b766a7a.tar.xz
KVM: arm64: Trap host SMCs in protected mode
While protected KVM is installed, start trapping all host SMCs. For now these are simply forwarded to EL3, except PSCI CPU_ON/CPU_SUSPEND/SYSTEM_SUSPEND which are intercepted and the hypervisor installed on newly booted cores. Create new constant HCR_HOST_NVHE_PROTECTED_FLAGS with the new set of HCR flags to use while the nVHE vector is installed when the kernel was booted with the protected flag enabled. Switch back to the default HCR flags when switching back to the stub vector. Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201202184122.26046-26-dbrazdil@google.com
-rw-r--r--arch/arm64/include/asm/kvm_arm.h1
-rw-r--r--arch/arm64/kvm/hyp/nvhe/hyp-init.S10
-rw-r--r--arch/arm64/kvm/hyp/nvhe/switch.c5
3 files changed, 15 insertions, 1 deletions
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 64ce29378467..4e90c2debf70 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -80,6 +80,7 @@
HCR_FMO | HCR_IMO | HCR_PTW )
#define HCR_VIRT_EXCP_MASK (HCR_VSE | HCR_VI | HCR_VF)
#define HCR_HOST_NVHE_FLAGS (HCR_RW | HCR_API | HCR_APK | HCR_ATA)
+#define HCR_HOST_NVHE_PROTECTED_FLAGS (HCR_HOST_NVHE_FLAGS | HCR_TSC)
#define HCR_HOST_VHE_FLAGS (HCR_RW | HCR_TGE | HCR_E2H)
/* TCR_EL2 Registers bits */
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-init.S b/arch/arm64/kvm/hyp/nvhe/hyp-init.S
index a2e251547625..31b060a44045 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-init.S
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-init.S
@@ -88,6 +88,11 @@ SYM_CODE_END(__kvm_hyp_init)
* x0: struct kvm_nvhe_init_params PA
*/
SYM_CODE_START_LOCAL(___kvm_hyp_init)
+alternative_if ARM64_KVM_PROTECTED_MODE
+ mov_q x1, HCR_HOST_NVHE_PROTECTED_FLAGS
+ msr hcr_el2, x1
+alternative_else_nop_endif
+
ldr x1, [x0, #NVHE_INIT_TPIDR_EL2]
msr tpidr_el2, x1
@@ -230,6 +235,11 @@ reset:
msr sctlr_el2, x5
isb
+alternative_if ARM64_KVM_PROTECTED_MODE
+ mov_q x5, HCR_HOST_NVHE_FLAGS
+ msr hcr_el2, x5
+alternative_else_nop_endif
+
/* Install stub vectors */
adr_l x5, __hyp_stub_vectors
msr vbar_el2, x5
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index 8ae8160bc93a..e1f8e0797144 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -96,7 +96,10 @@ static void __deactivate_traps(struct kvm_vcpu *vcpu)
mdcr_el2 |= MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT;
write_sysreg(mdcr_el2, mdcr_el2);
- write_sysreg(HCR_HOST_NVHE_FLAGS, hcr_el2);
+ if (is_protected_kvm_enabled())
+ write_sysreg(HCR_HOST_NVHE_PROTECTED_FLAGS, hcr_el2);
+ else
+ write_sysreg(HCR_HOST_NVHE_FLAGS, hcr_el2);
write_sysreg(CPTR_EL2_DEFAULT, cptr_el2);
write_sysreg(__kvm_hyp_host_vector, vbar_el2);
}