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| author | Marc Zyngier <maz@kernel.org> | 2023-02-09 20:58:16 +0300 |
|---|---|---|
| committer | Oliver Upton <oliver.upton@linux.dev> | 2023-02-11 13:13:29 +0300 |
| commit | d9552fe133f9f7c357460b041e2d3b20310adf8d (patch) | |
| tree | be2a0d3d3db5083e7a596dc9b29d1286b9815e8a /arch/arm64/kvm/hyp/vhe/switch.c | |
| parent | 9da117eec9243f41c349071773784ca5f9c5d473 (diff) | |
| download | linux-d9552fe133f9f7c357460b041e2d3b20310adf8d.tar.xz | |
KVM: arm64: nv: Emulate PSTATE.M for a guest hypervisor
We can no longer blindly copy the VCPU's PSTATE into SPSR_EL2 and return
to the guest and vice versa when taking an exception to the hypervisor,
because we emulate virtual EL2 in EL1 and therefore have to translate
the mode field from EL2 to EL1 and vice versa.
This requires keeping track of the state we enter the guest, for which
we transiently use a dedicated flag.
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230209175820.1939006-15-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Diffstat (limited to 'arch/arm64/kvm/hyp/vhe/switch.c')
| -rw-r--r-- | arch/arm64/kvm/hyp/vhe/switch.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c index 1a97391fedd2..76ea9392363d 100644 --- a/arch/arm64/kvm/hyp/vhe/switch.c +++ b/arch/arm64/kvm/hyp/vhe/switch.c @@ -120,6 +120,25 @@ static const exit_handler_fn *kvm_get_exit_handler_array(struct kvm_vcpu *vcpu) static void early_exit_filter(struct kvm_vcpu *vcpu, u64 *exit_code) { + /* + * If we were in HYP context on entry, adjust the PSTATE view + * so that the usual helpers work correctly. + */ + if (unlikely(vcpu_get_flag(vcpu, VCPU_HYP_CONTEXT))) { + u64 mode = *vcpu_cpsr(vcpu) & (PSR_MODE_MASK | PSR_MODE32_BIT); + + switch (mode) { + case PSR_MODE_EL1t: + mode = PSR_MODE_EL2t; + break; + case PSR_MODE_EL1h: + mode = PSR_MODE_EL2h; + break; + } + + *vcpu_cpsr(vcpu) &= ~(PSR_MODE_MASK | PSR_MODE32_BIT); + *vcpu_cpsr(vcpu) |= mode; + } } /* Switch to the guest for VHE systems running in EL2 */ @@ -154,6 +173,11 @@ static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) sysreg_restore_guest_state_vhe(guest_ctxt); __debug_switch_to_guest(vcpu); + if (is_hyp_ctxt(vcpu)) + vcpu_set_flag(vcpu, VCPU_HYP_CONTEXT); + else + vcpu_clear_flag(vcpu, VCPU_HYP_CONTEXT); + do { /* Jump in the fire! */ exit_code = __guest_enter(vcpu); |