Commit 917f9475 authored Jan 22, 2020 by Paolo Bonzini

KVM: x86: reorganize pvclock_gtod_data members



We will need a copy of tk->offs_boot in the next patch.  Store it and
cleanup the struct: instead of storing tk->tkr_xxx.base with the tk->offs_boot
included, store the raw value in struct pvclock_clock and sum it in
do_monotonic_raw and do_realtime.   tk->tkr_xxx.xtime_nsec also moves
to struct pvclock_clock.

While at it, fix a (usually harmless) typo in do_monotonic_raw, which
was using gtod->clock.shift instead of gtod->raw_clock.shift.

Fixes: 53fafdbb ("KVM: x86: switch KVMCLOCK base to monotonic raw clock")
Cc: stable@vger.kernel.org
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

parent 33aabd02

arch/x86/kvm/x86.c

+12 −17

Original line number	Diff line number	Diff line
		@@ -1610,6 +1610,8 @@ struct pvclock_clock {
		u64 mask;
		u32 mult;
		u32 shift;
		u64 base_cycles;
		u64 offset;
		};

		struct pvclock_gtod_data {
		@@ -1618,11 +1620,8 @@ struct pvclock_gtod_data {
		struct pvclock_clock clock; /* extract of a clocksource struct */
		struct pvclock_clock raw_clock; /* extract of a clocksource struct */

		u64 boot_ns_raw;
		u64 boot_ns;
		u64 nsec_base;
		ktime_t offs_boot;
		u64 wall_time_sec;
		u64 monotonic_raw_nsec;
		};

		static struct pvclock_gtod_data pvclock_gtod_data;
		@@ -1630,10 +1629,6 @@ static struct pvclock_gtod_data pvclock_gtod_data;
		static void update_pvclock_gtod(struct timekeeper *tk)
		{
		struct pvclock_gtod_data *vdata = &pvclock_gtod_data;
		u64 boot_ns, boot_ns_raw;

		boot_ns = ktime_to_ns(ktime_add(tk->tkr_mono.base, tk->offs_boot));
		boot_ns_raw = ktime_to_ns(ktime_add(tk->tkr_raw.base, tk->offs_boot));

		write_seqcount_begin(&vdata->seq);

		@@ -1643,20 +1638,20 @@ static void update_pvclock_gtod(struct timekeeper *tk)
		vdata->clock.mask = tk->tkr_mono.mask;
		vdata->clock.mult = tk->tkr_mono.mult;
		vdata->clock.shift = tk->tkr_mono.shift;
		vdata->clock.base_cycles = tk->tkr_mono.xtime_nsec;
		vdata->clock.offset = tk->tkr_mono.base;

		vdata->raw_clock.vclock_mode = tk->tkr_raw.clock->archdata.vclock_mode;
		vdata->raw_clock.cycle_last = tk->tkr_raw.cycle_last;
		vdata->raw_clock.mask = tk->tkr_raw.mask;
		vdata->raw_clock.mult = tk->tkr_raw.mult;
		vdata->raw_clock.shift = tk->tkr_raw.shift;

		vdata->boot_ns = boot_ns;
		vdata->nsec_base = tk->tkr_mono.xtime_nsec;
		vdata->raw_clock.base_cycles = tk->tkr_raw.xtime_nsec;
		vdata->raw_clock.offset = tk->tkr_raw.base;

		vdata->wall_time_sec = tk->xtime_sec;

		vdata->boot_ns_raw = boot_ns_raw;
		vdata->monotonic_raw_nsec = tk->tkr_raw.xtime_nsec;
		vdata->offs_boot = tk->offs_boot;

		write_seqcount_end(&vdata->seq);
		}
		@@ -2126,10 +2121,10 @@ static int do_monotonic_raw(s64 t, u64 tsc_timestamp)

		do {
		seq = read_seqcount_begin(&gtod->seq);
		ns = gtod->monotonic_raw_nsec;
		ns = gtod->raw_clock.base_cycles;
		ns += vgettsc(&gtod->raw_clock, tsc_timestamp, &mode);
		ns >>= gtod->clock.shift;
		ns += gtod->boot_ns_raw;
		ns >>= gtod->raw_clock.shift;
		ns += ktime_to_ns(ktime_add(gtod->raw_clock.offset, gtod->offs_boot));
		} while (unlikely(read_seqcount_retry(&gtod->seq, seq)));
		*t = ns;

		@@ -2146,7 +2141,7 @@ static int do_realtime(struct timespec64 ts, u64 tsc_timestamp)
		do {
		seq = read_seqcount_begin(&gtod->seq);
		ts->tv_sec = gtod->wall_time_sec;
		ns = gtod->nsec_base;
		ns = gtod->clock.base_cycles;
		ns += vgettsc(&gtod->clock, tsc_timestamp, &mode);
		ns >>= gtod->clock.shift;
		} while (unlikely(read_seqcount_retry(&gtod->seq, seq)));