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
This commit is contained in:
David Brazdil 2020-12-02 18:41:21 +00:00 committed by Marc Zyngier
parent fa8c3d6553
commit b93c17c418
3 changed files with 15 additions and 1 deletions

View File

@ -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 */

View File

@ -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

View File

@ -96,6 +96,9 @@ static void __deactivate_traps(struct kvm_vcpu *vcpu)
mdcr_el2 |= MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT;
write_sysreg(mdcr_el2, mdcr_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);