[PATCH v7 28/68] KVM: arm64: nv: Emulate EL12 register accesses from the virtual EL2
From: Marc Zyngier <maz@kernel.org>
Date: 2023-01-12 19:52:54
Also in:
kvm, kvmarm
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
From: Jintack Lim <redacted> With HCR_EL2.NV bit set, accesses to EL12 registers in the virtual EL2 trap to EL2. Handle those traps just like we do for EL1 registers. One exception is CNTKCTL_EL12. We don't trap on CNTKCTL_EL1 for non-VHE virtual EL2 because we don't have to. However, accessing CNTKCTL_EL12 will trap since it's one of the EL12 registers controlled by HCR_EL2.NV bit. Therefore, add a handler for it and don't treat it as a non-trap-registers when preparing a shadow context. These registers, being only a view on their EL1 counterpart, are permanently hidden from userspace. Reviewed-by: Alexandru Elisei <redacted> Signed-off-by: Jintack Lim <redacted> [maz: EL12_REG(), register visibility] Signed-off-by: Marc Zyngier <maz@kernel.org> --- arch/arm64/kvm/sys_regs.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 152b2e52ea47..f010e7073896 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c@@ -1703,6 +1703,26 @@ static unsigned int el2_visibility(const struct kvm_vcpu *vcpu, .val = v, \ } +/* + * EL{0,1}2 registers are the EL2 view on an EL0 or EL1 register when + * HCR_EL2.E2H==1, and only in the sysreg table for convenience of + * handling traps. Given that, they are always hidden from userspace. + */ +static unsigned int elx2_visibility(const struct kvm_vcpu *vcpu, + const struct sys_reg_desc *rd) +{ + return REG_HIDDEN_USER; +} + +#define EL12_REG(name, acc, rst, v) { \ + SYS_DESC(SYS_##name##_EL12), \ + .access = acc, \ + .reset = rst, \ + .reg = name##_EL1, \ + .val = v, \ + .visibility = elx2_visibility, \ +} + /* sys_reg_desc initialiser for known cpufeature ID registers */ #define ID_SANITISED(name) { \ SYS_DESC(SYS_##name), \
@@ -2282,6 +2302,23 @@ static const struct sys_reg_desc sys_reg_descs[] = { EL2_REG(CNTVOFF_EL2, access_rw, reset_val, 0), EL2_REG(CNTHCTL_EL2, access_rw, reset_val, 0), + EL12_REG(SCTLR, access_vm_reg, reset_val, 0x00C50078), + EL12_REG(CPACR, access_rw, reset_val, 0), + EL12_REG(TTBR0, access_vm_reg, reset_unknown, 0), + EL12_REG(TTBR1, access_vm_reg, reset_unknown, 0), + EL12_REG(TCR, access_vm_reg, reset_val, 0), + { SYS_DESC(SYS_SPSR_EL12), access_spsr}, + { SYS_DESC(SYS_ELR_EL12), access_elr}, + EL12_REG(AFSR0, access_vm_reg, reset_unknown, 0), + EL12_REG(AFSR1, access_vm_reg, reset_unknown, 0), + EL12_REG(ESR, access_vm_reg, reset_unknown, 0), + EL12_REG(FAR, access_vm_reg, reset_unknown, 0), + EL12_REG(MAIR, access_vm_reg, reset_unknown, 0), + EL12_REG(AMAIR, access_vm_reg, reset_amair_el1, 0), + EL12_REG(VBAR, access_rw, reset_val, 0), + EL12_REG(CONTEXTIDR, access_vm_reg, reset_val, 0), + EL12_REG(CNTKCTL, access_rw, reset_val, 0), + EL2_REG(SP_EL2, NULL, reset_unknown, 0), };
--
2.34.1
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