Commit 75807528 authored by Jingyi Wang's avatar Jingyi Wang Committed by lishusen
Browse files

KVM: arm64: Make use of TWED feature 

virt inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8WMG6


CVE: NA

-----------------------------

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 "twedel" to configure
the register.

Signed-off-by: default avatarZengruan Ye <yezengruan@huawei.com>
Signed-off-by: default avatarJingyi Wang <wangjingyi11@huawei.com>
Signed-off-by: default avatarlishusen <lishusen2@huawei.com>
parent d5925c19

arch/arm64/include/asm/kvm_arm.h

+7 −0
Original line number Diff line number Diff line
@@ -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

arch/arm64/include/asm/kvm_emulate.h

+21 −0
Original line number Diff line number Diff line
@@ -124,6 +124,27 @@ 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_set_twed(struct kvm_vcpu *vcpu)

{

	if (!cpus_have_const_cap(ARM64_HAS_TWED))

		return;



	if (twed_enable) {

		u64 delay = (u64)twedel;



		delay = (delay > HCR_TWEDEL_MAX) ? HCR_TWEDEL_MAX : delay;

		vcpu->arch.hcr_el2 |= HCR_TWEDEN;

		vcpu->arch.hcr_el2 &= ~HCR_TWEDEL_MASK;

		vcpu->arch.hcr_el2 |= (delay << HCR_TWEDEL_SHIFT);

	} else {

		vcpu->arch.hcr_el2 &= ~HCR_TWEDEN;

	}

}

#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);

arch/arm64/include/asm/kvm_host.h

+5 −0
Original line number Diff line number Diff line
@@ -1151,6 +1151,11 @@ void __init kvm_hyp_reserve(void); 
static inline void kvm_hyp_reserve(void) { }

#endif



#ifdef CONFIG_ARM64_TWED

extern bool twed_enable;

extern unsigned int twedel;

#endif



void kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu);

bool kvm_arm_vcpu_stopped(struct kvm_vcpu *vcpu);

arch/arm64/kvm/arm.c

+10 −0
Original line number Diff line number Diff line
@@ -64,6 +64,14 @@ bool is_kvm_arm_initialised(void) 
	return kvm_arm_initialised;

}



#ifdef CONFIG_ARM64_TWED

bool twed_enable;

module_param(twed_enable, bool, 0644);



unsigned int twedel;

module_param(twedel, uint, 0644);

#endif



int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)

{

	return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
@@ -983,6 +991,8 @@ 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

		 */