From: Marc Zyngier maz@kernel.org
mainline inclusion from mainline-v6.9-rc1 commit 6db55734ec4008da39e10d2fffa913fd9751ccaa category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8EC9K CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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Keeping host_debug_state on a per-vcpu basis is completely pointless. The lifetime of this data is only that of the inner run-loop, which means it is never accessed outside of the core EL2 code.
Move the structure into kvm_host_data, and save over 500 bytes per vcpu.
Reviewed-by: Suzuki K Poulose suzuki.poulose@arm.com Signed-off-by: Marc Zyngier maz@kernel.org Signed-off-by: Junhao He hejunhao3@huawei.com --- arch/arm64/include/asm/kvm_host.h | 31 +++++++++++++---------- arch/arm64/kvm/hyp/include/hyp/debug-sr.h | 4 +-- arch/arm64/kvm/hyp/nvhe/debug-sr.c | 8 +++--- 3 files changed, 23 insertions(+), 20 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index ea2f3c8fa0ba..1f6296bc1934 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -463,6 +463,19 @@ struct kvm_cpu_context { */ struct kvm_host_data { struct kvm_cpu_context host_ctxt; + + /* + * host_debug_state contains the host registers which are + * saved and restored during world switches. + */ + struct { + /* {Break,watch}point registers */ + struct kvm_guest_debug_arch regs; + /* Statistical profiling extension */ + u64 pmscr_el1; + /* Self-hosted trace */ + u64 trfcr_el1; + } host_debug_state; };
struct kvm_host_psci_config { @@ -556,11 +569,10 @@ struct kvm_vcpu_arch { * We maintain more than a single set of debug registers to support * debugging the guest from the host and to maintain separate host and * guest state during world switches. vcpu_debug_state are the debug - * registers of the vcpu as the guest sees them. host_debug_state are - * the host registers which are saved and restored during - * world switches. external_debug_state contains the debug - * values we want to debug the guest. This is set via the - * KVM_SET_GUEST_DEBUG ioctl. + * registers of the vcpu as the guest sees them. + * + * external_debug_state contains the debug values we want to debug the + * guest. This is set via the KVM_SET_GUEST_DEBUG ioctl. * * debug_ptr points to the set of debug registers that should be loaded * onto the hardware when running the guest. @@ -572,15 +584,6 @@ struct kvm_vcpu_arch { struct user_fpsimd_state *host_fpsimd_state; /* hyp VA */ struct task_struct *parent_task;
- struct { - /* {Break,watch}point registers */ - struct kvm_guest_debug_arch regs; - /* Statistical profiling extension */ - u64 pmscr_el1; - /* Self-hosted trace */ - u64 trfcr_el1; - } host_debug_state; - /* VGIC state */ struct vgic_cpu vgic_cpu; struct arch_timer_cpu timer_cpu; diff --git a/arch/arm64/kvm/hyp/include/hyp/debug-sr.h b/arch/arm64/kvm/hyp/include/hyp/debug-sr.h index eec0f8ccda56..d00093699aaf 100644 --- a/arch/arm64/kvm/hyp/include/hyp/debug-sr.h +++ b/arch/arm64/kvm/hyp/include/hyp/debug-sr.h @@ -137,7 +137,7 @@ static inline void __debug_switch_to_guest_common(struct kvm_vcpu *vcpu)
host_ctxt = host_data_ptr(host_ctxt); guest_ctxt = &vcpu->arch.ctxt; - host_dbg = &vcpu->arch.host_debug_state.regs; + host_dbg = host_data_ptr(host_debug_state.regs); guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr);
__debug_save_state(host_dbg, host_ctxt); @@ -156,7 +156,7 @@ static inline void __debug_switch_to_host_common(struct kvm_vcpu *vcpu)
host_ctxt = host_data_ptr(host_ctxt); guest_ctxt = &vcpu->arch.ctxt; - host_dbg = &vcpu->arch.host_debug_state.regs; + host_dbg = host_data_ptr(host_debug_state.regs); guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr);
__debug_save_state(guest_dbg, guest_ctxt); diff --git a/arch/arm64/kvm/hyp/nvhe/debug-sr.c b/arch/arm64/kvm/hyp/nvhe/debug-sr.c index 7746ea507b6f..53efda0235cf 100644 --- a/arch/arm64/kvm/hyp/nvhe/debug-sr.c +++ b/arch/arm64/kvm/hyp/nvhe/debug-sr.c @@ -83,10 +83,10 @@ void __debug_save_host_buffers_nvhe(struct kvm_vcpu *vcpu) { /* Disable and flush SPE data generation */ if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_SPE)) - __debug_save_spe(&vcpu->arch.host_debug_state.pmscr_el1); + __debug_save_spe(host_data_ptr(host_debug_state.pmscr_el1)); /* Disable and flush Self-Hosted Trace generation */ if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRBE)) - __debug_save_trace(&vcpu->arch.host_debug_state.trfcr_el1); + __debug_save_trace(host_data_ptr(host_debug_state.trfcr_el1)); }
void __debug_switch_to_guest(struct kvm_vcpu *vcpu) @@ -97,9 +97,9 @@ void __debug_switch_to_guest(struct kvm_vcpu *vcpu) void __debug_restore_host_buffers_nvhe(struct kvm_vcpu *vcpu) { if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_SPE)) - __debug_restore_spe(vcpu->arch.host_debug_state.pmscr_el1); + __debug_restore_spe(*host_data_ptr(host_debug_state.pmscr_el1)); if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRBE)) - __debug_restore_trace(vcpu->arch.host_debug_state.trfcr_el1); + __debug_restore_trace(*host_data_ptr(host_debug_state.trfcr_el1)); }
void __debug_switch_to_host(struct kvm_vcpu *vcpu)