[PATCH 5.5 259/367] KVM: x86: reorganize pvclock_gtod_data members

Greg Kroah-Hartman
2020-02-10T12:58:00Z

From: Paolo Bonzini <pbonzini@redhat.com>

commit 917f9475c0a8ab8958db7f22a5d495b9a1d51be6 upstream.

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: 53fafdbb8b21f ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/x86/kvm/x86.c | 29 ++++++++++++-----------------
1 file changed, 12 insertions(+), 17 deletions(-)

--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1580,6 +1580,8 @@ struct pvclock_clock {
u64 mask;
u32 mult;
u32 shift;
+ u64 base_cycles;
+ u64 offset;
};

struct pvclock_gtod_data {
@@ -1588,11 +1590,8 @@ 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;
@@ -1600,10 +1599,6 @@ static struct pvclock_gtod_data pvclock_
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);

@@ -1613,20 +1608,20 @@ static void update_pvclock_gtod(struct t
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);
}
@@ -2096,10 +2091,10 @@ static int do_monotonic_raw(s64 *t, u64

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;

@@ -2116,7 +2111,7 @@ static int do_realtime(struct timespec64
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)));