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Commit 381d585c authored by Haozhong Zhang's avatar Haozhong Zhang Committed by Paolo Bonzini
Browse files

KVM: x86: Replace call-back set_tsc_khz() with a common function 



Both VMX and SVM propagate virtual_tsc_khz in the same way, so this
patch removes the call-back set_tsc_khz() and replaces it with a common
function.

Signed-off-by: default avatarHaozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 35181e86

arch/x86/include/asm/kvm_host.h

+0 −1
Original line number Diff line number Diff line
@@ -853,7 +853,6 @@ struct kvm_x86_ops { 


	bool (*has_wbinvd_exit)(void);



	void (*set_tsc_khz)(struct kvm_vcpu *vcpu, u32 user_tsc_khz, bool scale);

	u64 (*read_tsc_offset)(struct kvm_vcpu *vcpu);

	void (*write_tsc_offset)(struct kvm_vcpu *vcpu, u64 offset);

arch/x86/kvm/svm.c

+0 −36
Original line number Diff line number Diff line
@@ -957,41 +957,6 @@ static void init_sys_seg(struct vmcb_seg *seg, uint32_t type) 
	seg->base = 0;

}



static void svm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz, bool scale)

{

	u64 ratio;

	u64 khz;



	/* Guest TSC same frequency as host TSC? */

	if (!scale) {

		vcpu->arch.tsc_scaling_ratio = TSC_RATIO_DEFAULT;

		return;

	}



	/* TSC scaling supported? */

	if (!boot_cpu_has(X86_FEATURE_TSCRATEMSR)) {

		if (user_tsc_khz > tsc_khz) {

			vcpu->arch.tsc_catchup = 1;

			vcpu->arch.tsc_always_catchup = 1;

		} else

			WARN(1, "user requested TSC rate below hardware speed\n");

		return;

	}



	khz = user_tsc_khz;



	/* TSC scaling required  - calculate ratio */

	ratio = khz << 32;

	do_div(ratio, tsc_khz);



	if (ratio == 0 || ratio & TSC_RATIO_RSVD) {

		WARN_ONCE(1, "Invalid TSC ratio - virtual-tsc-khz=%u\n",

				user_tsc_khz);

		return;

	}

	vcpu->arch.tsc_scaling_ratio = ratio;

}



static u64 svm_read_tsc_offset(struct kvm_vcpu *vcpu)

{

	struct vcpu_svm *svm = to_svm(vcpu);
@@ -4402,7 +4367,6 @@ static struct kvm_x86_ops svm_x86_ops = { 


	.has_wbinvd_exit = svm_has_wbinvd_exit,



	.set_tsc_khz = svm_set_tsc_khz,

	.read_tsc_offset = svm_read_tsc_offset,

	.write_tsc_offset = svm_write_tsc_offset,

	.adjust_tsc_offset = svm_adjust_tsc_offset,

arch/x86/kvm/vmx.c

+0 −17
Original line number Diff line number Diff line
@@ -2382,22 +2382,6 @@ static u64 vmx_read_l1_tsc(struct kvm_vcpu *vcpu, u64 host_tsc) 
	return host_tsc + tsc_offset;

}



/*

 * Engage any workarounds for mis-matched TSC rates.  Currently limited to

 * software catchup for faster rates on slower CPUs.

 */

static void vmx_set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz, bool scale)

{

	if (!scale)

		return;



	if (user_tsc_khz > tsc_khz) {

		vcpu->arch.tsc_catchup = 1;

		vcpu->arch.tsc_always_catchup = 1;

	} else

		WARN(1, "user requested TSC rate below hardware speed\n");

}



static u64 vmx_read_tsc_offset(struct kvm_vcpu *vcpu)

{

	return vmcs_read64(TSC_OFFSET);
@@ -10826,7 +10810,6 @@ static struct kvm_x86_ops vmx_x86_ops = { 


	.has_wbinvd_exit = cpu_has_vmx_wbinvd_exit,



	.set_tsc_khz = vmx_set_tsc_khz,

	.read_tsc_offset = vmx_read_tsc_offset,

	.write_tsc_offset = vmx_write_tsc_offset,

	.adjust_tsc_offset = vmx_adjust_tsc_offset,

arch/x86/kvm/x86.c

+41 −5
Original line number Diff line number Diff line
@@ -1253,7 +1253,43 @@ static u32 adjust_tsc_khz(u32 khz, s32 ppm) 
	return v;

}



static void kvm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 this_tsc_khz)

static int set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz, bool scale)

{

	u64 ratio;



	/* Guest TSC same frequency as host TSC? */

	if (!scale) {

		vcpu->arch.tsc_scaling_ratio = kvm_default_tsc_scaling_ratio;

		return 0;

	}



	/* TSC scaling supported? */

	if (!kvm_has_tsc_control) {

		if (user_tsc_khz > tsc_khz) {

			vcpu->arch.tsc_catchup = 1;

			vcpu->arch.tsc_always_catchup = 1;

			return 0;

		} else {

			WARN(1, "user requested TSC rate below hardware speed\n");

			return -1;

		}

	}



	/* TSC scaling required  - calculate ratio */

	ratio = mul_u64_u32_div(1ULL << kvm_tsc_scaling_ratio_frac_bits,

				user_tsc_khz, tsc_khz);



	if (ratio == 0 || ratio >= kvm_max_tsc_scaling_ratio) {

		WARN_ONCE(1, "Invalid TSC scaling ratio - virtual-tsc-khz=%u\n",

			  user_tsc_khz);

		return -1;

	}



	vcpu->arch.tsc_scaling_ratio = ratio;

	return 0;

}



static int kvm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 this_tsc_khz)

{

	u32 thresh_lo, thresh_hi;

	int use_scaling = 0;
@@ -1262,7 +1298,7 @@ static void kvm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 this_tsc_khz) 
	if (this_tsc_khz == 0) {

		/* set tsc_scaling_ratio to a safe value */

		vcpu->arch.tsc_scaling_ratio = kvm_default_tsc_scaling_ratio;

		return;

		return -1;

	}



	/* Compute a scale to convert nanoseconds in TSC cycles */
@@ -1283,7 +1319,7 @@ static void kvm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 this_tsc_khz) 
		pr_debug("kvm: requested TSC rate %u falls outside tolerance [%u,%u]\n", this_tsc_khz, thresh_lo, thresh_hi);

		use_scaling = 1;

	}

	kvm_x86_ops->set_tsc_khz(vcpu, this_tsc_khz, use_scaling);

	return set_tsc_khz(vcpu, this_tsc_khz, use_scaling);

}



static u64 compute_guest_tsc(struct kvm_vcpu *vcpu, s64 kernel_ns)
@@ -3353,9 +3389,9 @@ long kvm_arch_vcpu_ioctl(struct file *filp, 
		if (user_tsc_khz == 0)

			user_tsc_khz = tsc_khz;



		kvm_set_tsc_khz(vcpu, user_tsc_khz);



		if (!kvm_set_tsc_khz(vcpu, user_tsc_khz))

			r = 0;



		goto out;

	}

	case KVM_GET_TSC_KHZ: {

include/linux/math64.h

+29 −0
Original line number Diff line number Diff line
@@ -214,4 +214,33 @@ static inline u64 mul_u64_u64_shr(u64 a, u64 b, unsigned int shift) 


#endif



#ifndef mul_u64_u32_div

static inline u64 mul_u64_u32_div(u64 a, u32 mul, u32 divisor)

{

	union {

		u64 ll;

		struct {

#ifdef __BIG_ENDIAN

			u32 high, low;

#else

			u32 low, high;

#endif

		} l;

	} u, rl, rh;



	u.ll = a;

	rl.ll = (u64)u.l.low * mul;

	rh.ll = (u64)u.l.high * mul + rl.l.high;



	/* Bits 32-63 of the result will be in rh.l.low. */

	rl.l.high = do_div(rh.ll, divisor);



	/* Bits 0-31 of the result will be in rl.l.low.	*/

	do_div(rl.ll, divisor);



	rl.l.high = rh.l.low;

	return rl.ll;

}

#endif /* mul_u64_u32_div */



#endif /* _LINUX_MATH64_H */