[PATCH v5 11/37] KVM: arm64: Add TCR2_EL2 to the sysreg arrays

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

Add the TCR2_EL2 register to the per-vcpu sysreg register array,
the sysreg descriptor array, and advertise it as mapped to TCR2_EL1
for NV purposes.

Access to this register is conditional based on ID_AA64MMFR3_EL1.TCRX
being advertised.

Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/include/asm/kvm_host.h | 1 +
arch/arm64/kvm/sys_regs.c | 14 ++++++++++++++
2 files changed, 15 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 7f409dfc5cd4a..ca064af6cac21 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -492,6 +492,7 @@ enum vcpu_sysreg {

/* Anything from this can be RES0/RES1 sanitised */
MARKER(__SANITISED_REG_START__),
+ TCR2_EL2, /* Extended Translation Control Register (EL2) */

/* Any VNCR-capable reg goes after this point */
MARKER(__VNCR_START__),
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index d9c20563cae93..514b016d09764 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -134,6 +134,7 @@ static bool get_el2_to_el1_mapping(unsigned int reg,
MAPPED_EL2_SYSREG(ESR_EL2, ESR_EL1, NULL );
MAPPED_EL2_SYSREG(FAR_EL2, FAR_EL1, NULL );
MAPPED_EL2_SYSREG(MAIR_EL2, MAIR_EL1, NULL );
+ MAPPED_EL2_SYSREG(TCR2_EL2, TCR2_EL1, NULL );
MAPPED_EL2_SYSREG(AMAIR_EL2, AMAIR_EL1, NULL );
MAPPED_EL2_SYSREG(ELR_EL2, ELR_EL1, NULL );
MAPPED_EL2_SYSREG(SPSR_EL2, SPSR_EL1, NULL );
@@ -452,6 +453,18 @@ static bool access_vm_reg(struct kvm_vcpu *vcpu,
return true;
}

+static bool access_tcr2_el2(struct kvm_vcpu *vcpu,
+ struct sys_reg_params *p,
+ const struct sys_reg_desc *r)
+{
+ if (!kvm_has_feat(vcpu->kvm, ID_AA64MMFR3_EL1, TCRX, IMP)) {
+ kvm_inject_undefined(vcpu);
+ return false;
+ }
+
+ return access_rw(vcpu, p, r);
+}
+
static bool access_actlr(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *r)
@@ -2830,6 +2843,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
EL2_REG(TTBR0_EL2, access_rw, reset_val, 0),
EL2_REG(TTBR1_EL2, access_rw, reset_val, 0),
EL2_REG(TCR_EL2, access_rw, reset_val, TCR_EL2_RES1),
+ EL2_REG(TCR2_EL2, access_tcr2_el2, reset_val, TCR2_EL2_RES1),
EL2_REG_VNCR(VTTBR_EL2, reset_val, 0),
EL2_REG_VNCR(VTCR_EL2, reset_val, 0),

--
2.39.2