* [PATCH 1/3] x86/amd: revert commit 944e0fc51a89c9827b9
2018-05-30 11:09 [PATCH 0/3] Correct 4.9 stable commit 944e0fc51a89c98 Juergen Gross
@ 2018-05-30 11:09 ` Juergen Gross
2018-06-02 13:35 ` Patch "x86/amd: revert commit 944e0fc51a89c9827b9" has been added to the 4.9-stable tree gregkh
2018-05-30 11:09 ` [PATCH 1/3] x86/amd: revert commit 944e0fc51a89c9827b9 Juergen Gross
` (6 subsequent siblings)
7 siblings, 1 reply; 16+ messages in thread
From: Juergen Gross @ 2018-05-30 11:09 UTC (permalink / raw)
To: stable, xen-devel; +Cc: dwmw, boris.ostrovsky, Juergen Gross
Revert commit 944e0fc51a89c9827b98813d65dc083274777c7f ("x86/amd: don't
set X86_BUG_SYSRET_SS_ATTRS when running under Xen") as it is lacking
a prerequisite patch and is making things worse.
Signed-off-by: Juergen Gross <jgross@suse.com>
---
arch/x86/kernel/cpu/amd.c | 5 ++---
arch/x86/xen/enlighten.c | 4 +++-
2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 4c2be99fa0fb..cd0abf8ed314 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -857,9 +857,8 @@ static void init_amd(struct cpuinfo_x86 *c)
if (cpu_has(c, X86_FEATURE_3DNOW) || cpu_has(c, X86_FEATURE_LM))
set_cpu_cap(c, X86_FEATURE_3DNOWPREFETCH);
- /* AMD CPUs don't reset SS attributes on SYSRET, Xen does. */
- if (!cpu_has(c, X86_FEATURE_XENPV))
- set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
+ /* AMD CPUs don't reset SS attributes on SYSRET */
+ set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
}
#ifdef CONFIG_X86_32
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 081437b5f381..2bea87cc0ff2 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1977,8 +1977,10 @@ EXPORT_SYMBOL_GPL(xen_hvm_need_lapic);
static void xen_set_cpu_features(struct cpuinfo_x86 *c)
{
- if (xen_pv_domain())
+ if (xen_pv_domain()) {
+ clear_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
set_cpu_cap(c, X86_FEATURE_XENPV);
+ }
}
static void xen_pin_vcpu(int cpu)
--
2.13.6
^ permalink raw reply related [flat|nested] 16+ messages in thread* Patch "x86/amd: revert commit 944e0fc51a89c9827b9" has been added to the 4.9-stable tree
2018-05-30 11:09 ` [PATCH 1/3] x86/amd: revert commit 944e0fc51a89c9827b9 Juergen Gross
@ 2018-06-02 13:35 ` gregkh
0 siblings, 0 replies; 16+ messages in thread
From: gregkh @ 2018-06-02 13:35 UTC (permalink / raw)
To: boris.ostrovsky, dwmw, gregkh, jgross, xen-devel; +Cc: stable-commits
This is a note to let you know that I've just added the patch titled
x86/amd: revert commit 944e0fc51a89c9827b9
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-amd-revert-commit-944e0fc51a89c9827b9.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.
From foo@baz Sat Jun 2 15:10:07 CEST 2018
From: Juergen Gross <jgross@suse.com>
Date: Wed, 30 May 2018 13:09:56 +0200
Subject: x86/amd: revert commit 944e0fc51a89c9827b9
To: stable@vger.kernel.org, xen-devel@lists.xenproject.org
Cc: dwmw@amazon.co.uk, boris.ostrovsky@oracle.com, Juergen Gross <jgross@suse.com>
Message-ID: <20180530110958.19413-2-jgross@suse.com>
From: Juergen Gross <jgross@suse.com>
Revert commit 944e0fc51a89c9827b98813d65dc083274777c7f ("x86/amd: don't
set X86_BUG_SYSRET_SS_ATTRS when running under Xen") as it is lacking
a prerequisite patch and is making things worse.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/kernel/cpu/amd.c | 5 ++---
arch/x86/xen/enlighten.c | 4 +++-
2 files changed, 5 insertions(+), 4 deletions(-)
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -857,9 +857,8 @@ static void init_amd(struct cpuinfo_x86
if (cpu_has(c, X86_FEATURE_3DNOW) || cpu_has(c, X86_FEATURE_LM))
set_cpu_cap(c, X86_FEATURE_3DNOWPREFETCH);
- /* AMD CPUs don't reset SS attributes on SYSRET, Xen does. */
- if (!cpu_has(c, X86_FEATURE_XENPV))
- set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
+ /* AMD CPUs don't reset SS attributes on SYSRET */
+ set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
}
#ifdef CONFIG_X86_32
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1977,8 +1977,10 @@ EXPORT_SYMBOL_GPL(xen_hvm_need_lapic);
static void xen_set_cpu_features(struct cpuinfo_x86 *c)
{
- if (xen_pv_domain())
+ if (xen_pv_domain()) {
+ clear_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
set_cpu_cap(c, X86_FEATURE_XENPV);
+ }
}
static void xen_pin_vcpu(int cpu)
Patches currently in stable-queue which might be from jgross@suse.com are
queue-4.9/x86-amd-don-t-set-x86_bug_sysret_ss_attrs-when-running-under-xen.patch
queue-4.9/x86-amd-revert-commit-944e0fc51a89c9827b9.patch
queue-4.9/xen-set-cpu-capabilities-from-xen_start_kernel.patch
_______________________________________________
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Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply [flat|nested] 16+ messages in thread
* [PATCH 1/3] x86/amd: revert commit 944e0fc51a89c9827b9
2018-05-30 11:09 [PATCH 0/3] Correct 4.9 stable commit 944e0fc51a89c98 Juergen Gross
2018-05-30 11:09 ` [PATCH 1/3] x86/amd: revert commit 944e0fc51a89c9827b9 Juergen Gross
@ 2018-05-30 11:09 ` Juergen Gross
2018-05-30 11:09 ` [PATCH 2/3] xen: set cpu capabilities from xen_start_kernel() Juergen Gross
` (5 subsequent siblings)
7 siblings, 0 replies; 16+ messages in thread
From: Juergen Gross @ 2018-05-30 11:09 UTC (permalink / raw)
To: stable, xen-devel; +Cc: Juergen Gross, boris.ostrovsky, dwmw
Revert commit 944e0fc51a89c9827b98813d65dc083274777c7f ("x86/amd: don't
set X86_BUG_SYSRET_SS_ATTRS when running under Xen") as it is lacking
a prerequisite patch and is making things worse.
Signed-off-by: Juergen Gross <jgross@suse.com>
---
arch/x86/kernel/cpu/amd.c | 5 ++---
arch/x86/xen/enlighten.c | 4 +++-
2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 4c2be99fa0fb..cd0abf8ed314 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -857,9 +857,8 @@ static void init_amd(struct cpuinfo_x86 *c)
if (cpu_has(c, X86_FEATURE_3DNOW) || cpu_has(c, X86_FEATURE_LM))
set_cpu_cap(c, X86_FEATURE_3DNOWPREFETCH);
- /* AMD CPUs don't reset SS attributes on SYSRET, Xen does. */
- if (!cpu_has(c, X86_FEATURE_XENPV))
- set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
+ /* AMD CPUs don't reset SS attributes on SYSRET */
+ set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
}
#ifdef CONFIG_X86_32
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 081437b5f381..2bea87cc0ff2 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1977,8 +1977,10 @@ EXPORT_SYMBOL_GPL(xen_hvm_need_lapic);
static void xen_set_cpu_features(struct cpuinfo_x86 *c)
{
- if (xen_pv_domain())
+ if (xen_pv_domain()) {
+ clear_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
set_cpu_cap(c, X86_FEATURE_XENPV);
+ }
}
static void xen_pin_vcpu(int cpu)
--
2.13.6
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https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply related [flat|nested] 16+ messages in thread* [PATCH 2/3] xen: set cpu capabilities from xen_start_kernel()
2018-05-30 11:09 [PATCH 0/3] Correct 4.9 stable commit 944e0fc51a89c98 Juergen Gross
2018-05-30 11:09 ` [PATCH 1/3] x86/amd: revert commit 944e0fc51a89c9827b9 Juergen Gross
2018-05-30 11:09 ` [PATCH 1/3] x86/amd: revert commit 944e0fc51a89c9827b9 Juergen Gross
@ 2018-05-30 11:09 ` Juergen Gross
2018-05-30 11:09 ` Juergen Gross
` (4 subsequent siblings)
7 siblings, 0 replies; 16+ messages in thread
From: Juergen Gross @ 2018-05-30 11:09 UTC (permalink / raw)
To: stable, xen-devel; +Cc: Juergen Gross, boris.ostrovsky, dwmw
There is no need to set the same capabilities for each cpu
individually. This can easily be done for all cpus when starting the
kernel.
Upstream commit: 0808e80cb760de2733c0527d2090ed2205a1eef8 ("xen: set
cpu capabilities from xen_start_kernel()")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
arch/x86/xen/enlighten.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 2bea87cc0ff2..fb1867fedd29 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -471,6 +471,14 @@ static void __init xen_init_cpuid_mask(void)
cpuid_leaf1_ecx_set_mask = (1 << (X86_FEATURE_MWAIT % 32));
}
+static void __init xen_init_capabilities(void)
+{
+ if (xen_pv_domain()) {
+ setup_clear_cpu_cap(X86_BUG_SYSRET_SS_ATTRS);
+ setup_force_cpu_cap(X86_FEATURE_XENPV);
+ }
+}
+
static void xen_set_debugreg(int reg, unsigned long val)
{
HYPERVISOR_set_debugreg(reg, val);
@@ -1631,6 +1639,7 @@ asmlinkage __visible void __init xen_start_kernel(void)
xen_init_irq_ops();
xen_init_cpuid_mask();
+ xen_init_capabilities();
#ifdef CONFIG_X86_LOCAL_APIC
/*
@@ -1975,14 +1984,6 @@ bool xen_hvm_need_lapic(void)
}
EXPORT_SYMBOL_GPL(xen_hvm_need_lapic);
-static void xen_set_cpu_features(struct cpuinfo_x86 *c)
-{
- if (xen_pv_domain()) {
- clear_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
- set_cpu_cap(c, X86_FEATURE_XENPV);
- }
-}
-
static void xen_pin_vcpu(int cpu)
{
static bool disable_pinning;
@@ -2029,7 +2030,6 @@ const struct hypervisor_x86 x86_hyper_xen = {
.init_platform = xen_hvm_guest_init,
#endif
.x2apic_available = xen_x2apic_para_available,
- .set_cpu_features = xen_set_cpu_features,
.pin_vcpu = xen_pin_vcpu,
};
EXPORT_SYMBOL(x86_hyper_xen);
--
2.13.6
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Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply related [flat|nested] 16+ messages in thread* [PATCH 2/3] xen: set cpu capabilities from xen_start_kernel()
2018-05-30 11:09 [PATCH 0/3] Correct 4.9 stable commit 944e0fc51a89c98 Juergen Gross
` (2 preceding siblings ...)
2018-05-30 11:09 ` [PATCH 2/3] xen: set cpu capabilities from xen_start_kernel() Juergen Gross
@ 2018-05-30 11:09 ` Juergen Gross
2018-06-02 13:35 ` Patch "xen: set cpu capabilities from xen_start_kernel()" has been added to the 4.9-stable tree gregkh
2018-07-11 9:15 ` [PATCH 2/3] xen: set cpu capabilities from xen_start_kernel() Woodhouse, David
2018-05-30 11:09 ` [PATCH 3/3] x86/amd: don't set X86_BUG_SYSRET_SS_ATTRS when running under Xen Juergen Gross
` (3 subsequent siblings)
7 siblings, 2 replies; 16+ messages in thread
From: Juergen Gross @ 2018-05-30 11:09 UTC (permalink / raw)
To: stable, xen-devel; +Cc: dwmw, boris.ostrovsky, Juergen Gross
There is no need to set the same capabilities for each cpu
individually. This can easily be done for all cpus when starting the
kernel.
Upstream commit: 0808e80cb760de2733c0527d2090ed2205a1eef8 ("xen: set
cpu capabilities from xen_start_kernel()")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
arch/x86/xen/enlighten.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 2bea87cc0ff2..fb1867fedd29 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -471,6 +471,14 @@ static void __init xen_init_cpuid_mask(void)
cpuid_leaf1_ecx_set_mask = (1 << (X86_FEATURE_MWAIT % 32));
}
+static void __init xen_init_capabilities(void)
+{
+ if (xen_pv_domain()) {
+ setup_clear_cpu_cap(X86_BUG_SYSRET_SS_ATTRS);
+ setup_force_cpu_cap(X86_FEATURE_XENPV);
+ }
+}
+
static void xen_set_debugreg(int reg, unsigned long val)
{
HYPERVISOR_set_debugreg(reg, val);
@@ -1631,6 +1639,7 @@ asmlinkage __visible void __init xen_start_kernel(void)
xen_init_irq_ops();
xen_init_cpuid_mask();
+ xen_init_capabilities();
#ifdef CONFIG_X86_LOCAL_APIC
/*
@@ -1975,14 +1984,6 @@ bool xen_hvm_need_lapic(void)
}
EXPORT_SYMBOL_GPL(xen_hvm_need_lapic);
-static void xen_set_cpu_features(struct cpuinfo_x86 *c)
-{
- if (xen_pv_domain()) {
- clear_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
- set_cpu_cap(c, X86_FEATURE_XENPV);
- }
-}
-
static void xen_pin_vcpu(int cpu)
{
static bool disable_pinning;
@@ -2029,7 +2030,6 @@ const struct hypervisor_x86 x86_hyper_xen = {
.init_platform = xen_hvm_guest_init,
#endif
.x2apic_available = xen_x2apic_para_available,
- .set_cpu_features = xen_set_cpu_features,
.pin_vcpu = xen_pin_vcpu,
};
EXPORT_SYMBOL(x86_hyper_xen);
--
2.13.6
^ permalink raw reply related [flat|nested] 16+ messages in thread* Patch "xen: set cpu capabilities from xen_start_kernel()" has been added to the 4.9-stable tree
2018-05-30 11:09 ` Juergen Gross
@ 2018-06-02 13:35 ` gregkh
2018-07-11 9:15 ` [PATCH 2/3] xen: set cpu capabilities from xen_start_kernel() Woodhouse, David
1 sibling, 0 replies; 16+ messages in thread
From: gregkh @ 2018-06-02 13:35 UTC (permalink / raw)
To: boris.ostrovsky, dwmw, gregkh, jgross, xen-devel; +Cc: stable-commits
This is a note to let you know that I've just added the patch titled
xen: set cpu capabilities from xen_start_kernel()
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
xen-set-cpu-capabilities-from-xen_start_kernel.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.
From foo@baz Sat Jun 2 15:10:07 CEST 2018
From: Juergen Gross <jgross@suse.com>
Date: Wed, 30 May 2018 13:09:57 +0200
Subject: xen: set cpu capabilities from xen_start_kernel()
To: stable@vger.kernel.org, xen-devel@lists.xenproject.org
Cc: dwmw@amazon.co.uk, boris.ostrovsky@oracle.com, Juergen Gross <jgross@suse.com>
Message-ID: <20180530110958.19413-3-jgross@suse.com>
From: Juergen Gross <jgross@suse.com>
Upstream commit: 0808e80cb760de2733c0527d2090ed2205a1eef8 ("xen: set
cpu capabilities from xen_start_kernel()")
There is no need to set the same capabilities for each cpu
individually. This can easily be done for all cpus when starting the
kernel.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/xen/enlighten.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -471,6 +471,14 @@ static void __init xen_init_cpuid_mask(v
cpuid_leaf1_ecx_set_mask = (1 << (X86_FEATURE_MWAIT % 32));
}
+static void __init xen_init_capabilities(void)
+{
+ if (xen_pv_domain()) {
+ setup_clear_cpu_cap(X86_BUG_SYSRET_SS_ATTRS);
+ setup_force_cpu_cap(X86_FEATURE_XENPV);
+ }
+}
+
static void xen_set_debugreg(int reg, unsigned long val)
{
HYPERVISOR_set_debugreg(reg, val);
@@ -1631,6 +1639,7 @@ asmlinkage __visible void __init xen_sta
xen_init_irq_ops();
xen_init_cpuid_mask();
+ xen_init_capabilities();
#ifdef CONFIG_X86_LOCAL_APIC
/*
@@ -1975,14 +1984,6 @@ bool xen_hvm_need_lapic(void)
}
EXPORT_SYMBOL_GPL(xen_hvm_need_lapic);
-static void xen_set_cpu_features(struct cpuinfo_x86 *c)
-{
- if (xen_pv_domain()) {
- clear_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
- set_cpu_cap(c, X86_FEATURE_XENPV);
- }
-}
-
static void xen_pin_vcpu(int cpu)
{
static bool disable_pinning;
@@ -2029,7 +2030,6 @@ const struct hypervisor_x86 x86_hyper_xe
.init_platform = xen_hvm_guest_init,
#endif
.x2apic_available = xen_x2apic_para_available,
- .set_cpu_features = xen_set_cpu_features,
.pin_vcpu = xen_pin_vcpu,
};
EXPORT_SYMBOL(x86_hyper_xen);
Patches currently in stable-queue which might be from jgross@suse.com are
queue-4.9/x86-amd-don-t-set-x86_bug_sysret_ss_attrs-when-running-under-xen.patch
queue-4.9/x86-amd-revert-commit-944e0fc51a89c9827b9.patch
queue-4.9/xen-set-cpu-capabilities-from-xen_start_kernel.patch
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Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH 2/3] xen: set cpu capabilities from xen_start_kernel()
2018-05-30 11:09 ` Juergen Gross
2018-06-02 13:35 ` Patch "xen: set cpu capabilities from xen_start_kernel()" has been added to the 4.9-stable tree gregkh
@ 2018-07-11 9:15 ` Woodhouse, David
2018-07-11 9:46 ` Juergen Gross
2018-07-11 9:46 ` Juergen Gross
1 sibling, 2 replies; 16+ messages in thread
From: Woodhouse, David @ 2018-07-11 9:15 UTC (permalink / raw)
To: jgross@suse.com, stable@vger.kernel.org,
xen-devel@lists.xenproject.org
Cc: boris.ostrovsky@oracle.com, Veith, Simon
[-- Attachment #1.1: Type: text/plain, Size: 619 bytes --]
On Wed, 2018-05-30 at 13:09 +0200, Juergen Gross wrote:
> There is no need to set the same capabilities for each cpu
> individually. This can easily be done for all cpus when starting the
> kernel.
>
> Upstream commit: 0808e80cb760de2733c0527d2090ed2205a1eef8 ("xen: set
> cpu capabilities from xen_start_kernel()")
>
> Signed-off-by: Juergen Gross <jgross@suse.com>
> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
That breaks PV guests because they get KAISER enabled — when
kaiser_check_boottime_disable() runs, X86_FEATURE_XENPV isn't set.
Simon is testing, and about to send a fix...
[-- Attachment #1.2: smime.p7s --]
[-- Type: application/x-pkcs7-signature, Size: 5210 bytes --]
[-- Attachment #2.1: Type: text/plain, Size: 215 bytes --]
Amazon Development Centre (London) Ltd. Registered in England and Wales with registration number 04543232 with its registered office at 1 Principal Place, Worship Street, London EC2A 2FA, United Kingdom.
[-- Attachment #2.2: Type: text/html, Size: 228 bytes --]
[-- Attachment #3: Type: text/plain, Size: 157 bytes --]
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https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH 2/3] xen: set cpu capabilities from xen_start_kernel()
2018-07-11 9:15 ` [PATCH 2/3] xen: set cpu capabilities from xen_start_kernel() Woodhouse, David
@ 2018-07-11 9:46 ` Juergen Gross
2018-07-11 9:46 ` Juergen Gross
1 sibling, 0 replies; 16+ messages in thread
From: Juergen Gross @ 2018-07-11 9:46 UTC (permalink / raw)
To: Woodhouse, David, stable@vger.kernel.org,
xen-devel@lists.xenproject.org
Cc: boris.ostrovsky@oracle.com, Veith, Simon
On 11/07/18 11:15, Woodhouse, David wrote:
> On Wed, 2018-05-30 at 13:09 +0200, Juergen Gross wrote:
>> There is no need to set the same capabilities for each cpu
>> individually. This can easily be done for all cpus when starting the
>> kernel.
>>
>> Upstream commit: 0808e80cb760de2733c0527d2090ed2205a1eef8 ("xen: set
>> cpu capabilities from xen_start_kernel()")
>>
>> Signed-off-by: Juergen Gross <jgross@suse.com>
>> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
>
> That breaks PV guests because they get KAISER enabled — when
> kaiser_check_boottime_disable() runs, X86_FEATURE_XENPV isn't set.
Which kernel version are you talking about?
With upstream commit 60d3450167433f2d099ce2869dc52dd9e7dc9b29 which will
be part of next stable-4.9 everything is fine.
Juergen
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^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH 2/3] xen: set cpu capabilities from xen_start_kernel()
2018-07-11 9:15 ` [PATCH 2/3] xen: set cpu capabilities from xen_start_kernel() Woodhouse, David
2018-07-11 9:46 ` Juergen Gross
@ 2018-07-11 9:46 ` Juergen Gross
2018-07-11 9:54 ` Woodhouse, David
1 sibling, 1 reply; 16+ messages in thread
From: Juergen Gross @ 2018-07-11 9:46 UTC (permalink / raw)
To: Woodhouse, David, stable@vger.kernel.org,
xen-devel@lists.xenproject.org
Cc: boris.ostrovsky@oracle.com, Veith, Simon
On 11/07/18 11:15, Woodhouse, David wrote:
> On Wed, 2018-05-30 at 13:09 +0200, Juergen Gross wrote:
>> There is no need to set the same capabilities for each cpu
>> individually. This can easily be done for all cpus when starting the
>> kernel.
>>
>> Upstream commit: 0808e80cb760de2733c0527d2090ed2205a1eef8 ("xen: set
>> cpu capabilities from xen_start_kernel()")
>>
>> Signed-off-by: Juergen Gross <jgross@suse.com>
>> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
>
> That breaks PV guests because they get KAISER enabled — when
> kaiser_check_boottime_disable() runs, X86_FEATURE_XENPV isn't set.
Which kernel version are you talking about?
With upstream commit 60d3450167433f2d099ce2869dc52dd9e7dc9b29 which will
be part of next stable-4.9 everything is fine.
Juergen
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH 2/3] xen: set cpu capabilities from xen_start_kernel()
2018-07-11 9:46 ` Juergen Gross
@ 2018-07-11 9:54 ` Woodhouse, David
0 siblings, 0 replies; 16+ messages in thread
From: Woodhouse, David @ 2018-07-11 9:54 UTC (permalink / raw)
To: jgross@suse.com, stable@vger.kernel.org,
xen-devel@lists.xenproject.org
Cc: boris.ostrovsky@oracle.com, Veith, Simon
[-- Attachment #1.1: Type: text/plain, Size: 1011 bytes --]
On Wed, 2018-07-11 at 11:46 +0200, Juergen Gross wrote:
> On 11/07/18 11:15, Woodhouse, David wrote:
> >
> > On Wed, 2018-05-30 at 13:09 +0200, Juergen Gross wrote:
> > >
> > > There is no need to set the same capabilities for each cpu
> > > individually. This can easily be done for all cpus when starting the
> > > kernel.
> > >
> > > Upstream commit: 0808e80cb760de2733c0527d2090ed2205a1eef8 ("xen: set
> > > cpu capabilities from xen_start_kernel()")
> > >
> > > Signed-off-by: Juergen Gross <jgross@suse.com>
> > > Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> > That breaks PV guests because they get KAISER enabled — when
> > kaiser_check_boottime_disable() runs, X86_FEATURE_XENPV isn't set.
>
> Which kernel version are you talking about?
>
> With upstream commit 60d3450167433f2d099ce2869dc52dd9e7dc9b29 which will
> be part of next stable-4.9 everything is fine.
Right. That's what Simon had also backported. We hadn't spotted it was
already lined up.
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Amazon Development Centre (London) Ltd. Registered in England and Wales with registration number 04543232 with its registered office at 1 Principal Place, Worship Street, London EC2A 2FA, United Kingdom.
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^ permalink raw reply [flat|nested] 16+ messages in thread
* [PATCH 3/3] x86/amd: don't set X86_BUG_SYSRET_SS_ATTRS when running under Xen
2018-05-30 11:09 [PATCH 0/3] Correct 4.9 stable commit 944e0fc51a89c98 Juergen Gross
` (3 preceding siblings ...)
2018-05-30 11:09 ` Juergen Gross
@ 2018-05-30 11:09 ` Juergen Gross
2018-05-30 11:09 ` Juergen Gross
` (2 subsequent siblings)
7 siblings, 0 replies; 16+ messages in thread
From: Juergen Gross @ 2018-05-30 11:09 UTC (permalink / raw)
To: stable, xen-devel; +Cc: Juergen Gross, boris.ostrovsky, dwmw
When running as Xen pv guest X86_BUG_SYSRET_SS_ATTRS must not be set
on AMD cpus.
This bug/feature bit is kind of special as it will be used very early
when switching threads. Setting the bit and clearing it a little bit
later leaves a critical window where things can go wrong. This time
window has enlarged a little bit by using setup_clear_cpu_cap() instead
of the hypervisor's set_cpu_features callback. It seems this larger
window now makes it rather easy to hit the problem.
The proper solution is to never set the bit in case of Xen.
Upstream commit: def9331a12977770cc6132d79f8e6565871e8e38 ("x86/amd:
don't set X86_BUG_SYSRET_SS_ATTRS when running under Xen")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/kernel/cpu/amd.c | 5 +++--
arch/x86/xen/enlighten.c | 4 +---
2 files changed, 4 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index cd0abf8ed314..4c2be99fa0fb 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -857,8 +857,9 @@ static void init_amd(struct cpuinfo_x86 *c)
if (cpu_has(c, X86_FEATURE_3DNOW) || cpu_has(c, X86_FEATURE_LM))
set_cpu_cap(c, X86_FEATURE_3DNOWPREFETCH);
- /* AMD CPUs don't reset SS attributes on SYSRET */
- set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
+ /* AMD CPUs don't reset SS attributes on SYSRET, Xen does. */
+ if (!cpu_has(c, X86_FEATURE_XENPV))
+ set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
}
#ifdef CONFIG_X86_32
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index fb1867fedd29..a11b46f1abbd 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -473,10 +473,8 @@ static void __init xen_init_cpuid_mask(void)
static void __init xen_init_capabilities(void)
{
- if (xen_pv_domain()) {
- setup_clear_cpu_cap(X86_BUG_SYSRET_SS_ATTRS);
+ if (xen_pv_domain())
setup_force_cpu_cap(X86_FEATURE_XENPV);
- }
}
static void xen_set_debugreg(int reg, unsigned long val)
--
2.13.6
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^ permalink raw reply related [flat|nested] 16+ messages in thread* [PATCH 3/3] x86/amd: don't set X86_BUG_SYSRET_SS_ATTRS when running under Xen
2018-05-30 11:09 [PATCH 0/3] Correct 4.9 stable commit 944e0fc51a89c98 Juergen Gross
` (4 preceding siblings ...)
2018-05-30 11:09 ` [PATCH 3/3] x86/amd: don't set X86_BUG_SYSRET_SS_ATTRS when running under Xen Juergen Gross
@ 2018-05-30 11:09 ` Juergen Gross
2018-06-02 13:35 ` Patch "x86/amd: don't set X86_BUG_SYSRET_SS_ATTRS when running under Xen" has been added to the 4.9-stable tree gregkh
2018-06-02 13:11 ` [PATCH 0/3] Correct 4.9 stable commit 944e0fc51a89c98 Greg KH
2018-06-02 13:11 ` Greg KH
7 siblings, 1 reply; 16+ messages in thread
From: Juergen Gross @ 2018-05-30 11:09 UTC (permalink / raw)
To: stable, xen-devel; +Cc: dwmw, boris.ostrovsky, Juergen Gross
When running as Xen pv guest X86_BUG_SYSRET_SS_ATTRS must not be set
on AMD cpus.
This bug/feature bit is kind of special as it will be used very early
when switching threads. Setting the bit and clearing it a little bit
later leaves a critical window where things can go wrong. This time
window has enlarged a little bit by using setup_clear_cpu_cap() instead
of the hypervisor's set_cpu_features callback. It seems this larger
window now makes it rather easy to hit the problem.
The proper solution is to never set the bit in case of Xen.
Upstream commit: def9331a12977770cc6132d79f8e6565871e8e38 ("x86/amd:
don't set X86_BUG_SYSRET_SS_ATTRS when running under Xen")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/kernel/cpu/amd.c | 5 +++--
arch/x86/xen/enlighten.c | 4 +---
2 files changed, 4 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index cd0abf8ed314..4c2be99fa0fb 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -857,8 +857,9 @@ static void init_amd(struct cpuinfo_x86 *c)
if (cpu_has(c, X86_FEATURE_3DNOW) || cpu_has(c, X86_FEATURE_LM))
set_cpu_cap(c, X86_FEATURE_3DNOWPREFETCH);
- /* AMD CPUs don't reset SS attributes on SYSRET */
- set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
+ /* AMD CPUs don't reset SS attributes on SYSRET, Xen does. */
+ if (!cpu_has(c, X86_FEATURE_XENPV))
+ set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
}
#ifdef CONFIG_X86_32
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index fb1867fedd29..a11b46f1abbd 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -473,10 +473,8 @@ static void __init xen_init_cpuid_mask(void)
static void __init xen_init_capabilities(void)
{
- if (xen_pv_domain()) {
- setup_clear_cpu_cap(X86_BUG_SYSRET_SS_ATTRS);
+ if (xen_pv_domain())
setup_force_cpu_cap(X86_FEATURE_XENPV);
- }
}
static void xen_set_debugreg(int reg, unsigned long val)
--
2.13.6
^ permalink raw reply related [flat|nested] 16+ messages in thread* Patch "x86/amd: don't set X86_BUG_SYSRET_SS_ATTRS when running under Xen" has been added to the 4.9-stable tree
2018-05-30 11:09 ` Juergen Gross
@ 2018-06-02 13:35 ` gregkh
0 siblings, 0 replies; 16+ messages in thread
From: gregkh @ 2018-06-02 13:35 UTC (permalink / raw)
To: boris.ostrovsky, dwmw, gregkh, jgross, tglx, xen-devel; +Cc: stable-commits
This is a note to let you know that I've just added the patch titled
x86/amd: don't set X86_BUG_SYSRET_SS_ATTRS when running under Xen
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-amd-don-t-set-x86_bug_sysret_ss_attrs-when-running-under-xen.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.
From foo@baz Sat Jun 2 15:10:07 CEST 2018
From: Juergen Gross <jgross@suse.com>
Date: Wed, 30 May 2018 13:09:58 +0200
Subject: x86/amd: don't set X86_BUG_SYSRET_SS_ATTRS when running under Xen
To: stable@vger.kernel.org, xen-devel@lists.xenproject.org
Cc: dwmw@amazon.co.uk, boris.ostrovsky@oracle.com, Juergen Gross <jgross@suse.com>
Message-ID: <20180530110958.19413-4-jgross@suse.com>
From: Juergen Gross <jgross@suse.com>
Upstream commit: def9331a12977770cc6132d79f8e6565871e8e38 ("x86/amd:
don't set X86_BUG_SYSRET_SS_ATTRS when running under Xen")
When running as Xen pv guest X86_BUG_SYSRET_SS_ATTRS must not be set
on AMD cpus.
This bug/feature bit is kind of special as it will be used very early
when switching threads. Setting the bit and clearing it a little bit
later leaves a critical window where things can go wrong. This time
window has enlarged a little bit by using setup_clear_cpu_cap() instead
of the hypervisor's set_cpu_features callback. It seems this larger
window now makes it rather easy to hit the problem.
The proper solution is to never set the bit in case of Xen.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/kernel/cpu/amd.c | 5 +++--
arch/x86/xen/enlighten.c | 4 +---
2 files changed, 4 insertions(+), 5 deletions(-)
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -857,8 +857,9 @@ static void init_amd(struct cpuinfo_x86
if (cpu_has(c, X86_FEATURE_3DNOW) || cpu_has(c, X86_FEATURE_LM))
set_cpu_cap(c, X86_FEATURE_3DNOWPREFETCH);
- /* AMD CPUs don't reset SS attributes on SYSRET */
- set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
+ /* AMD CPUs don't reset SS attributes on SYSRET, Xen does. */
+ if (!cpu_has(c, X86_FEATURE_XENPV))
+ set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
}
#ifdef CONFIG_X86_32
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -473,10 +473,8 @@ static void __init xen_init_cpuid_mask(v
static void __init xen_init_capabilities(void)
{
- if (xen_pv_domain()) {
- setup_clear_cpu_cap(X86_BUG_SYSRET_SS_ATTRS);
+ if (xen_pv_domain())
setup_force_cpu_cap(X86_FEATURE_XENPV);
- }
}
static void xen_set_debugreg(int reg, unsigned long val)
Patches currently in stable-queue which might be from jgross@suse.com are
queue-4.9/x86-amd-don-t-set-x86_bug_sysret_ss_attrs-when-running-under-xen.patch
queue-4.9/x86-amd-revert-commit-944e0fc51a89c9827b9.patch
queue-4.9/xen-set-cpu-capabilities-from-xen_start_kernel.patch
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^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 0/3] Correct 4.9 stable commit 944e0fc51a89c98
2018-05-30 11:09 [PATCH 0/3] Correct 4.9 stable commit 944e0fc51a89c98 Juergen Gross
` (5 preceding siblings ...)
2018-05-30 11:09 ` Juergen Gross
@ 2018-06-02 13:11 ` Greg KH
2018-06-02 13:11 ` Greg KH
7 siblings, 0 replies; 16+ messages in thread
From: Greg KH @ 2018-06-02 13:11 UTC (permalink / raw)
To: Juergen Gross; +Cc: xen-devel, boris.ostrovsky, dwmw, stable
On Wed, May 30, 2018 at 01:09:55PM +0200, Juergen Gross wrote:
> Above commit is a wrong backport, as it is based on a missing
> prerequisite patch. Correct that by reverting said commit, include the
> missing patch, and do the backport correctly.
>
> Juergen Gross (3):
> x86/amd: revert commit 944e0fc51a89c9827b98813d65dc083274777c7f
> xen: set cpu capabilities from xen_start_kernel()
> x86/amd: don't set X86_BUG_SYSRET_SS_ATTRS when running under Xen
All now queued up, thanks.
greg k-h
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^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH 0/3] Correct 4.9 stable commit 944e0fc51a89c98
2018-05-30 11:09 [PATCH 0/3] Correct 4.9 stable commit 944e0fc51a89c98 Juergen Gross
` (6 preceding siblings ...)
2018-06-02 13:11 ` [PATCH 0/3] Correct 4.9 stable commit 944e0fc51a89c98 Greg KH
@ 2018-06-02 13:11 ` Greg KH
7 siblings, 0 replies; 16+ messages in thread
From: Greg KH @ 2018-06-02 13:11 UTC (permalink / raw)
To: Juergen Gross; +Cc: stable, xen-devel, dwmw, boris.ostrovsky
On Wed, May 30, 2018 at 01:09:55PM +0200, Juergen Gross wrote:
> Above commit is a wrong backport, as it is based on a missing
> prerequisite patch. Correct that by reverting said commit, include the
> missing patch, and do the backport correctly.
>
> Juergen Gross (3):
> x86/amd: revert commit 944e0fc51a89c9827b98813d65dc083274777c7f
> xen: set cpu capabilities from xen_start_kernel()
> x86/amd: don't set X86_BUG_SYSRET_SS_ATTRS when running under Xen
All now queued up, thanks.
greg k-h
^ permalink raw reply [flat|nested] 16+ messages in thread