From: "Cédric Le Goater" <clg@kaod.org>
To: David Gibson <david@gibson.dropbear.id.au>
Cc: qemu-devel@nongnu.org, "Cédric Le Goater" <clg@kaod.org>,
qemu-ppc@nongnu.org, "Greg Kurz" <groug@kaod.org>,
"Gustavo Romero" <gromero@linux.ibm.com>
Subject: [PATCH v2 3/6] spapr/xive: Add a warning when StoreEOI is activated on POWER9 CPUs
Date: Mon, 5 Oct 2020 18:51:44 +0200 [thread overview]
Message-ID: <20201005165147.526426-4-clg@kaod.org> (raw)
In-Reply-To: <20201005165147.526426-1-clg@kaod.org>
StoreEOI on POWER9 CPUs is racy because load-after-store ordering is
not enforced.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
hw/ppc/spapr_caps.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
index b0a9d0227db2..9251badbdc27 100644
--- a/hw/ppc/spapr_caps.c
+++ b/hw/ppc/spapr_caps.c
@@ -549,6 +549,15 @@ static void cap_storeeoi_apply(SpaprMachineState *spapr, uint8_t val,
error_setg(errp, "StoreEOI not supported by KVM");
return;
}
+
+ /*
+ * load-after-store ordering is not enforced on POWER9 CPUs
+ * and StoreEOI can be racy.
+ */
+ if (!ppc_type_check_compat(machine->cpu_type, CPU_POWERPC_LOGICAL_3_10,
+ 0, spapr->max_compat_pvr)) {
+ warn_report("StoreEOI on a POWER9 CPU is unsafe on KVM.");
+ }
}
}
--
2.25.4
next prev parent reply other threads:[~2020-10-05 16:53 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-05 16:51 [PATCH v2 0/6] spapr/xive: Activate StoreEOI in P10 compat guests Cédric Le Goater
2020-10-05 16:51 ` [PATCH v2 1/6] spapr/xive: Introduce a StoreEOI capability Cédric Le Goater
2020-10-06 16:42 ` Greg Kurz
2020-10-07 5:59 ` Cédric Le Goater
2020-10-07 7:24 ` Greg Kurz
2020-10-05 16:51 ` [PATCH v2 2/6] spapr/xive: Add a warning when StoreEOI is activated on POWER8 CPUs Cédric Le Goater
2020-10-06 16:52 ` Greg Kurz
2020-10-05 16:51 ` Cédric Le Goater [this message]
2020-10-06 16:58 ` [PATCH v2 3/6] spapr/xive: Add a warning when StoreEOI is activated on POWER9 CPUs Greg Kurz
2020-10-06 17:03 ` Cédric Le Goater
2020-10-07 8:56 ` Greg Kurz
2020-10-07 9:21 ` Cédric Le Goater
2020-10-05 16:51 ` [PATCH v2 4/6] spapr/xive: Enforce load-after-store ordering Cédric Le Goater
2020-10-06 17:02 ` Greg Kurz
2020-10-05 16:51 ` [PATCH v2 5/6] spapr/xive: Activate StoreEOI at the source level Cédric Le Goater
2020-10-06 17:06 ` Greg Kurz
2020-10-06 17:41 ` Cédric Le Goater
2020-10-07 7:26 ` Greg Kurz
2020-10-05 16:51 ` [PATCH v2 6/6] spapr/xive: Introduce a new CAS value for the StoreEOI capability Cédric Le Goater
2020-10-06 17:39 ` Greg Kurz
2020-10-06 17:56 ` Cédric Le Goater
2020-10-07 13:43 ` Greg Kurz
2020-10-07 14:28 ` Cédric Le Goater
2020-10-09 0:23 ` [PATCH v2 0/6] spapr/xive: Activate StoreEOI in P10 compat guests David Gibson
2020-10-09 5:57 ` Cédric Le Goater
2020-10-12 5:38 ` David Gibson
2020-11-02 13:22 ` Cédric Le Goater
2020-11-23 6:44 ` David Gibson
2020-11-23 11:16 ` Cédric Le Goater
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