[PATCH v2 08/21] arm64: KVM: Implement debug save/restore
Alex Bennée
alex.bennee at linaro.org
Mon Nov 30 04:00:24 PST 2015
Marc Zyngier <marc.zyngier at arm.com> writes:
> Implement the debug save restore as a direct translation of
> the assembly code version.
>
> Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
> ---
> arch/arm64/kvm/hyp/Makefile | 1 +
> arch/arm64/kvm/hyp/debug-sr.c | 130 ++++++++++++++++++++++++++++++++++++++++++
> arch/arm64/kvm/hyp/hyp.h | 9 +++
> 3 files changed, 140 insertions(+)
> create mode 100644 arch/arm64/kvm/hyp/debug-sr.c
>
> diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile
> index ec94200..ec14cac 100644
> --- a/arch/arm64/kvm/hyp/Makefile
> +++ b/arch/arm64/kvm/hyp/Makefile
> @@ -6,3 +6,4 @@ obj-$(CONFIG_KVM_ARM_HOST) += vgic-v2-sr.o
> obj-$(CONFIG_KVM_ARM_HOST) += vgic-v3-sr.o
> obj-$(CONFIG_KVM_ARM_HOST) += timer-sr.o
> obj-$(CONFIG_KVM_ARM_HOST) += sysreg-sr.o
> +obj-$(CONFIG_KVM_ARM_HOST) += debug-sr.o
> diff --git a/arch/arm64/kvm/hyp/debug-sr.c b/arch/arm64/kvm/hyp/debug-sr.c
> new file mode 100644
> index 0000000..a0b2b99
> --- /dev/null
> +++ b/arch/arm64/kvm/hyp/debug-sr.c
> @@ -0,0 +1,130 @@
> +/*
> + * Copyright (C) 2015 - ARM Ltd
> + * Author: Marc Zyngier <marc.zyngier at arm.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <linux/compiler.h>
> +#include <linux/kvm_host.h>
> +
> +#include <asm/kvm_mmu.h>
> +
> +#include "hyp.h"
> +
> +#define read_debug(r,n) read_sysreg(r##n##_el1)
> +#define write_debug(v,r,n) write_sysreg(v, r##n##_el1)
> +
> +#define save_debug(ptr,reg,nr) \
> + switch (nr) { \
> + case 15: ptr[15] = read_debug(reg, 15); \
> + case 14: ptr[14] = read_debug(reg, 14); \
> + case 13: ptr[13] = read_debug(reg, 13); \
> + case 12: ptr[12] = read_debug(reg, 12); \
> + case 11: ptr[11] = read_debug(reg, 11); \
> + case 10: ptr[10] = read_debug(reg, 10); \
> + case 9: ptr[9] = read_debug(reg, 9); \
> + case 8: ptr[8] = read_debug(reg, 8); \
> + case 7: ptr[7] = read_debug(reg, 7); \
> + case 6: ptr[6] = read_debug(reg, 6); \
> + case 5: ptr[5] = read_debug(reg, 5); \
> + case 4: ptr[4] = read_debug(reg, 4); \
> + case 3: ptr[3] = read_debug(reg, 3); \
> + case 2: ptr[2] = read_debug(reg, 2); \
> + case 1: ptr[1] = read_debug(reg, 1); \
> + default: ptr[0] = read_debug(reg, 0); \
> + }
> +
> +#define restore_debug(ptr,reg,nr) \
> + switch (nr) { \
> + case 15: write_debug(ptr[15], reg, 15); \
> + case 14: write_debug(ptr[14], reg, 14); \
> + case 13: write_debug(ptr[13], reg, 13); \
> + case 12: write_debug(ptr[12], reg, 12); \
> + case 11: write_debug(ptr[11], reg, 11); \
> + case 10: write_debug(ptr[10], reg, 10); \
> + case 9: write_debug(ptr[9], reg, 9); \
> + case 8: write_debug(ptr[8], reg, 8); \
> + case 7: write_debug(ptr[7], reg, 7); \
> + case 6: write_debug(ptr[6], reg, 6); \
> + case 5: write_debug(ptr[5], reg, 5); \
> + case 4: write_debug(ptr[4], reg, 4); \
> + case 3: write_debug(ptr[3], reg, 3); \
> + case 2: write_debug(ptr[2], reg, 2); \
> + case 1: write_debug(ptr[1], reg, 1); \
> + default: write_debug(ptr[0], reg, 0); \
> + }
> +
> +void __hyp_text __debug_save_state(struct kvm_vcpu *vcpu,
> + struct kvm_guest_debug_arch *dbg,
> + struct kvm_cpu_context *ctxt)
> +{
> + if (vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY) {
> + u64 aa64dfr0 = read_sysreg(id_aa64dfr0_el1);
> + int brps, wrps;
> +
> + brps = (aa64dfr0 >> 12) & 0xf;
> + wrps = (aa64dfr0 >> 20) & 0xf;
I'm sure we have that defined - get_num_brps/wrps() - but I don't know
if the compiler would do a better job with it.
> +
> + save_debug(dbg->dbg_bcr, dbgbcr, brps);
> + save_debug(dbg->dbg_bvr, dbgbvr, brps);
> + save_debug(dbg->dbg_wcr, dbgwcr, wrps);
> + save_debug(dbg->dbg_wvr, dbgwvr, wrps);
> +
> + ctxt->sys_regs[MDCCINT_EL1] = read_sysreg(mdccint_el1);
> + }
> +}
> +
> +void __hyp_text __debug_restore_state(struct kvm_vcpu *vcpu,
> + struct kvm_guest_debug_arch *dbg,
> + struct kvm_cpu_context *ctxt)
> +{
> + if (vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY) {
> + u64 aa64dfr0 = read_sysreg(id_aa64dfr0_el1);
> + int brps, wrps;
> +
> + brps = (aa64dfr0 >> 12) & 0xf;
> + wrps = (aa64dfr0 >> 20) & 0xf;
> +
> + restore_debug(dbg->dbg_bcr, dbgbcr, brps);
> + restore_debug(dbg->dbg_bvr, dbgbvr, brps);
> + restore_debug(dbg->dbg_wcr, dbgwcr, wrps);
> + restore_debug(dbg->dbg_wvr, dbgwvr, wrps);
> +
> + write_sysreg(ctxt->sys_regs[MDCCINT_EL1], mdccint_el1);
> + }
> +}
> +
> +void __hyp_text __debug_cond_save_host_state(struct kvm_vcpu *vcpu)
> +{
> + if ((vcpu->arch.ctxt.sys_regs[MDSCR_EL1] & DBG_MDSCR_KDE) ||
> + (vcpu->arch.ctxt.sys_regs[MDSCR_EL1] & DBG_MDSCR_KDE))
> + vcpu->arch.debug_flags |= KVM_ARM64_DEBUG_DIRTY;
> +
> + __debug_save_state(vcpu, &vcpu->arch.host_debug_state,
> + kern_hyp_va(vcpu->arch.host_cpu_context));
> +}
> +
> +void __hyp_text __debug_cond_restore_host_state(struct kvm_vcpu *vcpu)
> +{
> + if (vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY) {
> + __debug_restore_state(vcpu, &vcpu->arch.host_debug_state,
> + kern_hyp_va(vcpu->arch.host_cpu_context));
> + vcpu->arch.debug_flags &= ~KVM_ARM64_DEBUG_DIRTY;
> + }
> +}
> +
> +u32 __hyp_text __debug_read_mdcr_el2(void)
> +{
> + return read_sysreg(mdcr_el2);
> +}
> diff --git a/arch/arm64/kvm/hyp/hyp.h b/arch/arm64/kvm/hyp/hyp.h
> index 4639330..2581232 100644
> --- a/arch/arm64/kvm/hyp/hyp.h
> +++ b/arch/arm64/kvm/hyp/hyp.h
> @@ -41,5 +41,14 @@ void __sysreg_restore_state(struct kvm_cpu_context *ctxt);
> void __sysreg32_save_state(struct kvm_vcpu *vcpu);
> void __sysreg32_restore_state(struct kvm_vcpu *vcpu);
>
> +void __debug_save_state(struct kvm_vcpu *vcpu,
> + struct kvm_guest_debug_arch *dbg,
> + struct kvm_cpu_context *ctxt);
> +void __debug_restore_state(struct kvm_vcpu *vcpu,
> + struct kvm_guest_debug_arch *dbg,
> + struct kvm_cpu_context *ctxt);
> +void __debug_cond_save_host_state(struct kvm_vcpu *vcpu);
> +void __debug_cond_restore_host_state(struct kvm_vcpu *vcpu);
> +
> #endif /* __ARM64_KVM_HYP_H__ */
I spun it up against my KVM debug tests and everything was fine. Have a:
Tested-by: Alex Bennée <alex.bennee at linaro.org>
Reviewed-by: Alex Bennée <alex.bennee at linaro.org>
--
Alex Bennée
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