From: Jingyi Wang wangjingyi11@huawei.com
virt inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8WMG6 CVE: NA
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For HCR_EL2, TWEDEn(bit[59]) decides whether TWED is enabled, and when the configurable delay is enabled, TWEDEL (bits[63:60]) encodes the minimum delay in taking a trap of WFE caused by the TWE bit in this register as 2^(TWEDEL + 8) cycles.
We use two kernel parameters "twed_enable" and "twe_delay" to configure the register.
Signed-off-by: Zengruan Ye yezengruan@huawei.com Signed-off-by: Jingyi Wang wangjingyi11@huawei.com Signed-off-by: lishusen lishusen2@huawei.com --- arch/arm64/include/asm/kvm_arm.h | 7 +++++ arch/arm64/include/asm/kvm_emulate.h | 44 ++++++++++++++++++++++++++++ arch/arm64/include/asm/kvm_host.h | 5 ++++ arch/arm64/kvm/arm.c | 10 +++++++ 4 files changed, 66 insertions(+)
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index 1095c6647e96..62056554b8a6 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -14,6 +14,7 @@
/* Hyp Configuration Register (HCR) bits */
+#define HCR_TWEDEN (UL(1) << 59) #define HCR_TID5 (UL(1) << 58) #define HCR_DCT (UL(1) << 57) #define HCR_ATA_SHIFT 56 @@ -74,6 +75,12 @@ #define HCR_VM (UL(1) << 0) #define HCR_RES0 ((UL(1) << 48) | (UL(1) << 39))
+#ifdef CONFIG_ARM64_TWED +#define HCR_TWEDEL_SHIFT 60 +#define HCR_TWEDEL_MAX (UL(0xf)) +#define HCR_TWEDEL_MASK (HCR_TWEDEL_MAX << HCR_TWEDEL_SHIFT) +#endif + /* * The bits we set in HCR: * TLOR: Trap LORegion register accesses diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h index 3d6725ff0bf6..3592a1d944e4 100644 --- a/arch/arm64/include/asm/kvm_emulate.h +++ b/arch/arm64/include/asm/kvm_emulate.h @@ -124,6 +124,50 @@ static inline void vcpu_set_wfx_traps(struct kvm_vcpu *vcpu) vcpu->arch.hcr_el2 |= HCR_TWI; }
+#ifdef CONFIG_ARM64_TWED +static inline void vcpu_twed_enable(struct kvm_vcpu *vcpu) +{ + if (!cpus_have_const_cap(ARM64_HAS_TWED)) + return; + + vcpu->arch.hcr_el2 |= HCR_TWEDEN; +} + +static inline void vcpu_twed_disable(struct kvm_vcpu *vcpu) +{ + if (!cpus_have_const_cap(ARM64_HAS_TWED)) + return; + + vcpu->arch.hcr_el2 &= ~HCR_TWEDEN; +} + +static inline void vcpu_set_twe_delay(struct kvm_vcpu *vcpu) +{ + if (!cpus_have_const_cap(ARM64_HAS_TWED)) + return; + + u64 delay = (u64)twe_delay; + + if (delay > HCR_TWEDEL_MAX) + delay = HCR_TWEDEL_MAX; + + vcpu->arch.hcr_el2 &= ~HCR_TWEDEL_MASK; + vcpu->arch.hcr_el2 |= (delay << HCR_TWEDEL_SHIFT); +} + +static inline void vcpu_set_twed(struct kvm_vcpu *vcpu) +{ + if (cpus_have_const_cap(ARM64_HAS_TWED) && twed_enable) { + vcpu_twed_enable(vcpu); + vcpu_set_twe_delay(vcpu); + } else { + vcpu_twed_disable(vcpu); + } +} +#else +static inline void vcpu_set_twed(struct kvm_vcpu *vcpu) {} +#endif + static inline void vcpu_ptrauth_enable(struct kvm_vcpu *vcpu) { vcpu->arch.hcr_el2 |= (HCR_API | HCR_APK); diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 44c6110172db..4fa43e797e63 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -1167,6 +1167,11 @@ static inline void kvm_hyp_reserve(void) { } void kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu); bool kvm_arm_vcpu_stopped(struct kvm_vcpu *vcpu);
+#ifdef CONFIG_ARM64_TWED +extern bool twed_enable; +extern unsigned int twe_delay; +#endif + extern bool kvm_ncsnp_support; extern bool kvm_dvmbm_support;
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 09682bbcbdf5..742c714a0d08 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -72,6 +72,14 @@ bool is_kvm_arm_initialised(void) return kvm_arm_initialised; }
+#ifdef CONFIG_ARM64_TWED +bool twed_enable; +module_param(twed_enable, bool, S_IRUGO | S_IWUSR); + +unsigned int twe_delay; +module_param(twe_delay, uint, S_IRUGO | S_IWUSR); +#endif + int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu) { return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE; @@ -1010,6 +1018,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) kvm_arm_setup_debug(vcpu); kvm_arch_vcpu_ctxflush_fp(vcpu);
+ vcpu_set_twed(vcpu); + /************************************************************** * Enter the guest */