[PATCH v5 08/37] KVM: arm64: Correctly access TCR2_EL1, PIR_EL1, PIRE0_EL1 with VHE

Marc Zyngier
2024-10-23T14:53:52Z

For code that accesses any of the guest registers for emulation
purposes, it is crucial to know where the most up-to-date data is.

While this is pretty clear for nVHE (memory is the sole repository),
things are a lot muddier for VHE, as depending on the SYSREGS_ON_CPU
flag, registers can either be loaded on the HW or be in memory.

Even worse with NV, where the loaded state is by definition partial.

For these reasons, KVM offers the vcpu_read_sys_reg() and
vcpu_write_sys_reg() primitives that always do the right thing.
However, these primitive must know what register to access, and
this is the role of the __vcpu_read_sys_reg_from_cpu() and
__vcpu_write_sys_reg_to_cpu() helpers.

As it turns out, TCR2_EL1, PIR_EL1, PIRE0_EL1 and not described
in the latter helpers, meaning that the AT code cannot use them
to emulate S1PIE.

Add the three registers to the (long) list.

Fixes: 86f9de9db178 ("KVM: arm64: Save/restore PIE registers")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: Joey Gouly <joey.gouly@arm.com>
---
arch/arm64/include/asm/kvm_host.h | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 329619c6fa961..1adf68971bb17 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -1030,6 +1030,9 @@ static inline bool __vcpu_read_sys_reg_from_cpu(int reg, u64 *val)
case TTBR0_EL1: *val = read_sysreg_s(SYS_TTBR0_EL12); break;
case TTBR1_EL1: *val = read_sysreg_s(SYS_TTBR1_EL12); break;
case TCR_EL1: *val = read_sysreg_s(SYS_TCR_EL12); break;
+ case TCR2_EL1: *val = read_sysreg_s(SYS_TCR2_EL12); break;
+ case PIR_EL1: *val = read_sysreg_s(SYS_PIR_EL12); break;
+ case PIRE0_EL1: *val = read_sysreg_s(SYS_PIRE0_EL12); break;
case ESR_EL1: *val = read_sysreg_s(SYS_ESR_EL12); break;
case AFSR0_EL1: *val = read_sysreg_s(SYS_AFSR0_EL12); break;
case AFSR1_EL1: *val = read_sysreg_s(SYS_AFSR1_EL12); break;
@@ -1076,6 +1079,9 @@ static inline bool __vcpu_write_sys_reg_to_cpu(u64 val, int reg)
case TTBR0_EL1: write_sysreg_s(val, SYS_TTBR0_EL12); break;
case TTBR1_EL1: write_sysreg_s(val, SYS_TTBR1_EL12); break;
case TCR_EL1: write_sysreg_s(val, SYS_TCR_EL12); break;
+ case TCR2_EL1: write_sysreg_s(val, SYS_TCR2_EL12); break;
+ case PIR_EL1: write_sysreg_s(val, SYS_PIR_EL12); break;
+ case PIRE0_EL1: write_sysreg_s(val, SYS_PIRE0_EL12); break;
case ESR_EL1: write_sysreg_s(val, SYS_ESR_EL12); break;
case AFSR0_EL1: write_sysreg_s(val, SYS_AFSR0_EL12); break;
case AFSR1_EL1: write_sysreg_s(val, SYS_AFSR1_EL12); break;
--
2.39.2