From 1700f89cb99aae19e4f8ec38b1b59f3b7ae71b91 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 14 Jun 2023 16:51:29 +0100 Subject: [PATCH] KVM: arm64: Fix hVHE init on CPUs where HCR_EL2.E2H is not RES1 On CPUs where E2H is RES1, we very quickly set the scene for running EL2 with a VHE configuration, as we do not have any other choice. However, CPUs that conform to the current writing of the architecture start with E2H=0, and only later upgrade with E2H=1. This is all good, but nothing there is actually reconfiguring EL2 to be able to correctly run the kernel at EL1. Huhuh... The "obvious" solution is not to just reinitialise the timer controls like we do, but to really intitialise *everything* unconditionally. This requires a bit of surgery, and is a good opportunity to remove the macro that messes with SPSR_EL2 in init_el2_state. With that, hVHE now works correctly on my trusted A55 machine! Reported-by: Oliver Upton Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20230614155129.2697388-1-maz@kernel.org Signed-off-by: Oliver Upton --- arch/arm64/include/asm/el2_setup.h | 1 - arch/arm64/kernel/head.S | 2 ++ arch/arm64/kvm/hyp/nvhe/hyp-init.S | 19 ++++++++++++------- 3 files changed, 14 insertions(+), 8 deletions(-) diff --git a/arch/arm64/include/asm/el2_setup.h b/arch/arm64/include/asm/el2_setup.h index bba508f..5a353f9 100644 --- a/arch/arm64/include/asm/el2_setup.h +++ b/arch/arm64/include/asm/el2_setup.h @@ -205,7 +205,6 @@ __init_el2_nvhe_idregs __init_el2_cptr __init_el2_fgt - __init_el2_nvhe_prepare_eret .endm #ifndef __KVM_NVHE_HYPERVISOR__ diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index e92caeb..2395505 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -603,6 +603,8 @@ SYM_INNER_LABEL(init_el2, SYM_L_LOCAL) msr sctlr_el1, x1 mov x2, xzr 2: + __init_el2_nvhe_prepare_eret + mov w0, #BOOT_CPU_MODE_EL2 orr x0, x0, x2 eret diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-init.S b/arch/arm64/kvm/hyp/nvhe/hyp-init.S index f9ee10e..74ee77d 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-init.S +++ b/arch/arm64/kvm/hyp/nvhe/hyp-init.S @@ -83,9 +83,6 @@ SYM_CODE_END(__kvm_hyp_init) * x0: struct kvm_nvhe_init_params PA */ SYM_CODE_START_LOCAL(___kvm_hyp_init) - ldr x1, [x0, #NVHE_INIT_TPIDR_EL2] - msr tpidr_el2, x1 - ldr x1, [x0, #NVHE_INIT_STACK_HYP_VA] mov sp, x1 @@ -99,11 +96,18 @@ SYM_CODE_START_LOCAL(___kvm_hyp_init) and x2, x1, x2 cbz x2, 1f - mrs x1, cnthctl_el2 - and x1, x1, #~(BIT(0) | BIT(1)) - orr x1, x1, #(BIT(10) | BIT(11)) - msr cnthctl_el2, x1 + // hVHE: Replay the EL2 setup to account for the E2H bit + // TPIDR_EL2 is used to preserve x0 across the macro maze... + isb + msr tpidr_el2, x0 + init_el2_state + finalise_el2_state + mrs x0, tpidr_el2 + 1: + ldr x1, [x0, #NVHE_INIT_TPIDR_EL2] + msr tpidr_el2, x1 + ldr x1, [x0, #NVHE_INIT_VTTBR] msr vttbr_el2, x1 @@ -193,6 +197,7 @@ SYM_CODE_START_LOCAL(__kvm_hyp_init_cpu) /* Initialize EL2 CPU state to sane values. */ init_el2_state // Clobbers x0..x2 finalise_el2_state + __init_el2_nvhe_prepare_eret /* Enable MMU, set vectors and stack. */ mov x0, x28 -- 2.7.4