Re: [PATCH v4 03/15] KVM: arm64: MDCR_EL2 is a 64-bit register
From: Marc Zyngier <maz@kernel.org>
Date: 2021-08-18 14:34:15
Also in:
kvmarm, linux-arm-kernel
On Tue, 17 Aug 2021 09:11:22 +0100, Fuad Tabba [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Fix the places in KVM that treat MDCR_EL2 as a 32-bit register. More recent features (e.g., FEAT_SPEv1p2) use bits above 31. No functional change intended. Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Fuad Tabba <redacted> --- arch/arm64/include/asm/kvm_arm.h | 20 ++++++++++---------- arch/arm64/include/asm/kvm_asm.h | 2 +- arch/arm64/include/asm/kvm_host.h | 2 +- arch/arm64/kvm/debug.c | 2 +- arch/arm64/kvm/hyp/nvhe/debug-sr.c | 2 +- arch/arm64/kvm/hyp/vhe/debug-sr.c | 2 +- 6 files changed, 15 insertions(+), 15 deletions(-)diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index d436831dd706..6a523ec83415 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h@@ -281,18 +281,18 @@ /* Hyp Debug Configuration Register bits */ #define MDCR_EL2_E2TB_MASK (UL(0x3)) #define MDCR_EL2_E2TB_SHIFT (UL(24)) -#define MDCR_EL2_TTRF (1 << 19) -#define MDCR_EL2_TPMS (1 << 14) +#define MDCR_EL2_TTRF (UL(1) << 19) +#define MDCR_EL2_TPMS (UL(1) << 14) #define MDCR_EL2_E2PB_MASK (UL(0x3)) #define MDCR_EL2_E2PB_SHIFT (UL(12)) -#define MDCR_EL2_TDRA (1 << 11) -#define MDCR_EL2_TDOSA (1 << 10) -#define MDCR_EL2_TDA (1 << 9) -#define MDCR_EL2_TDE (1 << 8) -#define MDCR_EL2_HPME (1 << 7) -#define MDCR_EL2_TPM (1 << 6) -#define MDCR_EL2_TPMCR (1 << 5) -#define MDCR_EL2_HPMN_MASK (0x1F) +#define MDCR_EL2_TDRA (UL(1) << 11) +#define MDCR_EL2_TDOSA (UL(1) << 10) +#define MDCR_EL2_TDA (UL(1) << 9) +#define MDCR_EL2_TDE (UL(1) << 8) +#define MDCR_EL2_HPME (UL(1) << 7) +#define MDCR_EL2_TPM (UL(1) << 6) +#define MDCR_EL2_TPMCR (UL(1) << 5) +#define MDCR_EL2_HPMN_MASK (UL(0x1F)) /* For compatibility with fault code shared with 32-bit */ #define FSC_FAULT ESR_ELx_FSC_FAULTdiff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index 9f0bf2109be7..63ead9060ab5 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h@@ -210,7 +210,7 @@ extern u64 __vgic_v3_read_vmcr(void); extern void __vgic_v3_write_vmcr(u32 vmcr); extern void __vgic_v3_init_lrs(void); -extern u32 __kvm_get_mdcr_el2(void); +extern u64 __kvm_get_mdcr_el2(void); #define __KVM_EXTABLE(from, to) \ " .pushsection __kvm_ex_table, \"a\"\n" \diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 347781f99b6a..4d2d974c1522 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h@@ -289,7 +289,7 @@ struct kvm_vcpu_arch { /* HYP configuration */ u64 hcr_el2; - u32 mdcr_el2; + u64 mdcr_el2;
This breaks an existing trace in debug.c::kvm_arm_setup_mdcr_el2():
trace_kvm_arm_set_dreg32("MDCR_EL2", vcpu->arch.mdcr_el2);
which expects a 32bit value. I guess we could add an equivalent 64bit
version, or silently upgrade the tracepoint to take a 64bit value.
None of them are good solutions, but hey, something has to give...
Thanks,
M.
--
Without deviation from the norm, progress is not possible.