Commit 629b5348 authored by Joao Martins's avatar Joao Martins Committed by David Woodhouse
Browse files

KVM: x86/xen: update wallclock region 



Wallclock on Xen is written in the shared_info page.

To that purpose, export kvm_write_wall_clock() and pass on the GPA of
its location to populate the shared_info wall clock data.

Signed-off-by: default avatarJoao Martins <joao.m.martins@oracle.com>
Signed-off-by: default avatarDavid Woodhouse <dwmw@amazon.co.uk>
parent 42387042

arch/x86/kvm/x86.c

+12 −5
Original line number Diff line number Diff line
@@ -1949,15 +1949,14 @@ static s64 get_kvmclock_base_ns(void) 
}

#endif



static void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock)

void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock, int sec_hi_ofs)

{

	int version;

	int r;

	struct pvclock_wall_clock wc;

	u32 wc_sec_hi;

	u64 wall_nsec;



	kvm->arch.wall_clock = wall_clock;



	if (!wall_clock)

		return;
@@ -1986,6 +1985,12 @@ static void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock) 


	kvm_write_guest(kvm, wall_clock, &wc, sizeof(wc));



	if (sec_hi_ofs) {

		wc_sec_hi = wall_nsec >> 32;

		kvm_write_guest(kvm, wall_clock + sec_hi_ofs,

				&wc_sec_hi, sizeof(wc_sec_hi));

	}



	version++;

	kvm_write_guest(kvm, wall_clock, &version, sizeof(version));

}
@@ -3131,13 +3136,15 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) 
		if (!guest_pv_has(vcpu, KVM_FEATURE_CLOCKSOURCE2))

			return 1;



		kvm_write_wall_clock(vcpu->kvm, data);

		vcpu->kvm->arch.wall_clock = data;

		kvm_write_wall_clock(vcpu->kvm, data, 0);

		break;

	case MSR_KVM_WALL_CLOCK:

		if (!guest_pv_has(vcpu, KVM_FEATURE_CLOCKSOURCE))

			return 1;



		kvm_write_wall_clock(vcpu->kvm, data);

		vcpu->kvm->arch.wall_clock = data;

		kvm_write_wall_clock(vcpu->kvm, data, 0);

		break;

	case MSR_KVM_SYSTEM_TIME_NEW:

		if (!guest_pv_has(vcpu, KVM_FEATURE_CLOCKSOURCE2))

arch/x86/kvm/x86.h

+1 −0
Original line number Diff line number Diff line
@@ -247,6 +247,7 @@ static inline bool kvm_vcpu_latch_init(struct kvm_vcpu *vcpu) 
	return is_smm(vcpu) || static_call(kvm_x86_apic_init_signal_blocked)(vcpu);

}



void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock, int sec_hi_ofs);

void kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq, int inc_eip);



void kvm_write_tsc(struct kvm_vcpu *vcpu, struct msr_data *msr);

arch/x86/kvm/xen.c

+30 −3
Original line number Diff line number Diff line
@@ -21,15 +21,42 @@ DEFINE_STATIC_KEY_DEFERRED_FALSE(kvm_xen_enabled, HZ); 


static int kvm_xen_shared_info_init(struct kvm *kvm, gfn_t gfn)

{

	gpa_t gpa = gfn_to_gpa(gfn);

	int wc_ofs, sec_hi_ofs;

	int ret;

	int idx = srcu_read_lock(&kvm->srcu);



	ret = kvm_gfn_to_hva_cache_init(kvm, &kvm->arch.xen.shinfo_cache,

					gfn_to_gpa(gfn), PAGE_SIZE);

	if (!ret) {

					gpa, PAGE_SIZE);

	if (ret)

		goto out;



	kvm->arch.xen.shinfo_set = true;



	/* Paranoia checks on the 32-bit struct layout */

	BUILD_BUG_ON(offsetof(struct compat_shared_info, wc) != 0x900);

	BUILD_BUG_ON(offsetof(struct compat_shared_info, arch.wc_sec_hi) != 0x924);

	BUILD_BUG_ON(offsetof(struct pvclock_vcpu_time_info, version) != 0);



	/* 32-bit location by default */

	wc_ofs = offsetof(struct compat_shared_info, wc);

	sec_hi_ofs = offsetof(struct compat_shared_info, arch.wc_sec_hi);



#ifdef CONFIG_X86_64

	/* Paranoia checks on the 64-bit struct layout */

	BUILD_BUG_ON(offsetof(struct shared_info, wc) != 0xc00);

	BUILD_BUG_ON(offsetof(struct shared_info, wc_sec_hi) != 0xc0c);



	if (kvm->arch.xen.long_mode) {

		wc_ofs = offsetof(struct shared_info, wc);

		sec_hi_ofs = offsetof(struct shared_info, wc_sec_hi);

	}

#endif



	kvm_write_wall_clock(kvm, gpa + wc_ofs, sec_hi_ofs - wc_ofs);

	kvm_make_all_cpus_request(kvm, KVM_REQ_MASTERCLOCK_UPDATE);



out:

	srcu_read_unlock(&kvm->srcu, idx);

	return ret;

}