[PATCH v5 18/37] KVM: arm64: Add AT fast-path support for S1PIE

Marc Zyngier
2024-10-23T14:53:54Z

Emulating AT using AT instructions requires that the live state
matches the translation regime the AT instruction targets.

If targeting the EL1&0 translation regime and that S1PIE is
supported, we also need to restore that state (covering TCR2_EL1,
PIR_EL1, and PIRE0_EL1).

Add the required system register switcheroo.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/at.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)

diff --git a/arch/arm64/kvm/at.c b/arch/arm64/kvm/at.c
index f04677127fbc0..b9d0992e91972 100644
--- a/arch/arm64/kvm/at.c
+++ b/arch/arm64/kvm/at.c
@@ -412,6 +412,9 @@ struct mmu_config {
u64 ttbr1;
u64 tcr;
u64 mair;
+ u64 tcr2;
+ u64 pir;
+ u64 pire0;
u64 sctlr;
u64 vttbr;
u64 vtcr;
@@ -424,6 +427,13 @@ static void __mmu_config_save(struct mmu_config *config)
config->ttbr1 = read_sysreg_el1(SYS_TTBR1);
config->tcr = read_sysreg_el1(SYS_TCR);
config->mair = read_sysreg_el1(SYS_MAIR);
+ if (cpus_have_final_cap(ARM64_HAS_TCR2)) {
+ config->tcr2 = read_sysreg_el1(SYS_TCR2);
+ if (cpus_have_final_cap(ARM64_HAS_S1PIE)) {
+ config->pir = read_sysreg_el1(SYS_PIR);
+ config->pire0 = read_sysreg_el1(SYS_PIRE0);
+ }
+ }
config->sctlr = read_sysreg_el1(SYS_SCTLR);
config->vttbr = read_sysreg(vttbr_el2);
config->vtcr = read_sysreg(vtcr_el2);
@@ -444,6 +454,13 @@ static void __mmu_config_restore(struct mmu_config *config)
write_sysreg_el1(config->ttbr1, SYS_TTBR1);
write_sysreg_el1(config->tcr, SYS_TCR);
write_sysreg_el1(config->mair, SYS_MAIR);
+ if (cpus_have_final_cap(ARM64_HAS_TCR2)) {
+ write_sysreg_el1(config->tcr2, SYS_TCR2);
+ if (cpus_have_final_cap(ARM64_HAS_S1PIE)) {
+ write_sysreg_el1(config->pir, SYS_PIR);
+ write_sysreg_el1(config->pire0, SYS_PIRE0);
+ }
+ }
write_sysreg_el1(config->sctlr, SYS_SCTLR);
write_sysreg(config->vttbr, vttbr_el2);
write_sysreg(config->vtcr, vtcr_el2);
@@ -914,6 +931,13 @@ static u64 __kvm_at_s1e01_fast(struct kvm_vcpu *vcpu, u32 op, u64 vaddr)
write_sysreg_el1(vcpu_read_sys_reg(vcpu, TTBR1_EL1), SYS_TTBR1);
write_sysreg_el1(vcpu_read_sys_reg(vcpu, TCR_EL1), SYS_TCR);
write_sysreg_el1(vcpu_read_sys_reg(vcpu, MAIR_EL1), SYS_MAIR);
+ if (kvm_has_feat(vcpu->kvm, ID_AA64MMFR3_EL1, TCRX, IMP)) {
+ write_sysreg_el1(vcpu_read_sys_reg(vcpu, TCR2_EL1), SYS_TCR2);
+ if (kvm_has_feat(vcpu->kvm, ID_AA64MMFR3_EL1, S1PIE, IMP)) {
+ write_sysreg_el1(vcpu_read_sys_reg(vcpu, PIR_EL1), SYS_PIR);
+ write_sysreg_el1(vcpu_read_sys_reg(vcpu, PIRE0_EL1), SYS_PIRE0);
+ }
+ }
write_sysreg_el1(vcpu_read_sys_reg(vcpu, SCTLR_EL1), SYS_SCTLR);
__load_stage2(mmu, mmu->arch);

--
2.39.2