linux-kernel - [PATCH 5.5 259/367] KVM: x86: reorganize pvclock_gtod

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Message-Id: <20200210122448.554018214@linuxfoundation.org>
Date:   Mon, 10 Feb 2020 04:32:52 -0800
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Vitaly Kuznetsov <vkuznets@...hat.com>,
        Paolo Bonzini <pbonzini@...hat.com>
Subject: [PATCH 5.5 259/367] KVM: x86: reorganize pvclock_gtod_data members

From: Paolo Bonzini <pbonzini@...hat.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@...r.kernel.org
Reviewed-by: Vitaly Kuznetsov <vkuznets@...hat.com>
Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.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)));