From: David Gibson <david@gibson.dropbear.id.au>
To: peter.maydell@linaro.org
Cc: lvivier@redhat.com, aik@ozlabs.ru, qemu-devel@nongnu.org,
"Maxiwell S. Garcia" <maxiwell@linux.ibm.com>,
groug@kaod.org, qemu-ppc@nongnu.org,
David Gibson <david@gibson.dropbear.id.au>
Subject: [Qemu-devel] [PULL 05/42] migration: Do not re-read the clock on pre_save in case of paused guest
Date: Wed, 21 Aug 2019 17:25:05 +1000 [thread overview]
Message-ID: <20190821072542.23090-6-david@gibson.dropbear.id.au> (raw)
In-Reply-To: <20190821072542.23090-1-david@gibson.dropbear.id.au>
From: "Maxiwell S. Garcia" <maxiwell@linux.ibm.com>
Re-read the timebase before migrate was ported from x86 commit:
6053a86fe7bd: kvmclock: reduce kvmclock difference on migration
The clock move makes the guest knows about the paused time between
the stop and migrate commands. This is an issue in an already-paused
VM because some side effects, like process stalls, could happen
after migration.
So, this patch checks the runstate of guest in the pre_save handler and
do not re-reads the timebase in case of paused state (cold migration).
Signed-off-by: Maxiwell S. Garcia <maxiwell@linux.ibm.com>
Message-Id: <20190711194702.26598-1-maxiwell@linux.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
hw/ppc/ppc.c | 13 +++++++++----
target/ppc/cpu-qom.h | 1 +
2 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/hw/ppc/ppc.c b/hw/ppc/ppc.c
index 7963feeab4..52a18eb7d7 100644
--- a/hw/ppc/ppc.c
+++ b/hw/ppc/ppc.c
@@ -1011,6 +1011,8 @@ static void timebase_save(PPCTimebase *tb)
* there is no need to update it from KVM here
*/
tb->guest_timebase = ticks + first_ppc_cpu->env.tb_env->tb_offset;
+
+ tb->runstate_paused = runstate_check(RUN_STATE_PAUSED);
}
static void timebase_load(PPCTimebase *tb)
@@ -1054,9 +1056,9 @@ void cpu_ppc_clock_vm_state_change(void *opaque, int running,
}
/*
- * When migrating, read the clock just before migration,
- * so that the guest clock counts during the events
- * between:
+ * When migrating a running guest, read the clock just
+ * before migration, so that the guest clock counts
+ * during the events between:
*
* * vm_stop()
* *
@@ -1071,7 +1073,10 @@ static int timebase_pre_save(void *opaque)
{
PPCTimebase *tb = opaque;
- timebase_save(tb);
+ /* guest_timebase won't be overridden in case of paused guest */
+ if (!tb->runstate_paused) {
+ timebase_save(tb);
+ }
return 0;
}
diff --git a/target/ppc/cpu-qom.h b/target/ppc/cpu-qom.h
index a2f202f021..5769fb78a9 100644
--- a/target/ppc/cpu-qom.h
+++ b/target/ppc/cpu-qom.h
@@ -201,6 +201,7 @@ typedef struct PowerPCCPUClass {
typedef struct PPCTimebase {
uint64_t guest_timebase;
int64_t time_of_the_day_ns;
+ bool runstate_paused;
} PPCTimebase;
extern const VMStateDescription vmstate_ppc_timebase;
--
2.21.0
next prev parent reply other threads:[~2019-08-21 7:27 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-21 7:25 [Qemu-devel] [PULL 00/42] ppc-for-4.2 queue 20190821 David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 01/42] spapr: quantify error messages regarding capability settings David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 02/42] spapr_iommu: Fix xlate trace to print translated address David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 03/42] hw: add compat machines for 4.2 David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 04/42] spapr_pci: Allow 2MiB and 16MiB IOMMU pagesizes by default David Gibson
2019-08-21 7:25 ` David Gibson [this message]
2019-08-21 7:25 ` [Qemu-devel] [PULL 06/42] target/ppc: Optimize emulation of lvsl and lvsr instructions David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 07/42] target/ppc: Optimize emulation of vsl and vsr instructions David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 08/42] target/ppc: move opcode decode tables to PowerPCCPU David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 09/42] target/ppc: Optimize emulation of vgbbd instruction David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 10/42] target/ppc: Optimize emulation of vclzd instruction David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 11/42] target/ppc: Optimize emulation of vclzw instruction David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 12/42] ppc: fix memory leak in spapr_caps_add_properties David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 13/42] ppc: fix memory leak in spapr_dt_drc() David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 14/42] ppc: fix leak in h_client_architecture_support David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 15/42] spapr: Implement dispatch tracking for tcg David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 16/42] spapr: Implement H_PROD David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 17/42] spapr: Implement H_CONFER David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 18/42] spapr: Implement H_JOIN David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 19/42] docs/specs: initial spec summary for Ultravisor-related hcalls David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 20/42] spapr: initial implementation for H_TPM_COMM/spapr-tpm-proxy David Gibson
2019-09-09 17:23 ` Peter Maydell
2019-09-09 17:51 ` Greg Kurz
2019-08-21 7:25 ` [Qemu-devel] [PULL 21/42] pseries: Update SLOF firmware image David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 22/42] ppc/xive: use an abstract type for XiveNotifier David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 23/42] ppc/xive: Implement TM_PULL_OS_CTX special command David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 24/42] ppc/xive: Provide backlog support David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 25/42] ppc/xive: Provide escalation support David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 26/42] ppc/xive: Provide unconditional " David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 27/42] ppc/xive: Provide silent " David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 28/42] ppc/xive: Improve 'info pic' support David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 29/42] machine: Add wakeup method to MachineClass David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 30/42] i386: use machine class ->wakeup method David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 31/42] spapr: Implement ibm,suspend-me David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 32/42] ppc: remove idle_timer logic David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 33/42] spapr/pci: Consolidate de-allocation of MSIs David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 34/42] spapr/pci: Free MSIs during reset David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 35/42] spapr/irq: Drop spapr_irq_msi_reset() David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 36/42] spapr: Implement better workaround in spapr-vty device David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 37/42] spapr/xive: Mask the EAS when allocating an IRQ David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 38/42] target/ppc: Add Directed Privileged Door-bell Exception State (DPDES) SPR David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 39/42] ppc: Add support for 'mffsl' instruction David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 40/42] ppc: conform to processor User's Manual for xscvdpspn David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 41/42] ppc: Fix emulated INFINITY and NAN conversions David Gibson
2019-08-21 7:25 ` [Qemu-devel] [PULL 42/42] ppc: Fix emulated single to double denormalized conversions David Gibson
2019-08-21 8:25 ` [Qemu-devel] [PULL 00/42] ppc-for-4.2 queue 20190821 no-reply
2019-08-21 14:18 ` Peter Maydell
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