2022-11-04 07:54:53

by Jürgen Groß

Subject: [PATCH v2 5/5] x86: switch to cpu_feature_enabled() for X86_FEATURE_XENPV

Convert the remaining cases of static_cpu_has(X86_FEATURE_XENPV) and
boot_cpu_has(X86_FEATURE_XENPV) to use cpu_feature_enabled(), allowing
more efficient code in case the kernel is configured without
CONFIG_XEN_PV.

Signed-off-by: Juergen Gross <[email protected]>
---
arch/x86/kernel/cpu/amd.c | 2 +-
arch/x86/kernel/cpu/bugs.c | 2 +-
arch/x86/kernel/cpu/hygon.c | 2 +-
arch/x86/kernel/process_64.c | 4 ++--
arch/x86/kernel/topology.c | 2 +-
5 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 860b60273df3..697fe881e967 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -985,7 +985,7 @@ static void init_amd(struct cpuinfo_x86 *c)
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))
+ if (!cpu_feature_enabled(X86_FEATURE_XENPV))
set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);

/*
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index da7c361f47e0..7f78e1527c5e 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -1302,7 +1302,7 @@ static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void)
return SPECTRE_V2_CMD_AUTO;
}

- if (cmd == SPECTRE_V2_CMD_IBRS && boot_cpu_has(X86_FEATURE_XENPV)) {
+ if (cmd == SPECTRE_V2_CMD_IBRS && cpu_feature_enabled(X86_FEATURE_XENPV)) {
pr_err("%s selected but running as XenPV guest. Switching to AUTO select\n",
mitigation_options[i].option);
return SPECTRE_V2_CMD_AUTO;
diff --git a/arch/x86/kernel/cpu/hygon.c b/arch/x86/kernel/cpu/hygon.c
index 21fd425088fe..1c27645fd429 100644
--- a/arch/x86/kernel/cpu/hygon.c
+++ b/arch/x86/kernel/cpu/hygon.c
@@ -339,7 +339,7 @@ static void init_hygon(struct cpuinfo_x86 *c)
set_cpu_cap(c, X86_FEATURE_ARAT);

/* Hygon CPUs don't reset SS attributes on SYSRET, Xen does. */
- if (!cpu_has(c, X86_FEATURE_XENPV))
+ if (!cpu_feature_enabled(X86_FEATURE_XENPV))
set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);

check_null_seg_clears_base(c);
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 6b3418bff326..e2f469175be8 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -165,7 +165,7 @@ static noinstr unsigned long __rdgsbase_inactive(void)

lockdep_assert_irqs_disabled();

- if (!static_cpu_has(X86_FEATURE_XENPV)) {
+ if (!cpu_feature_enabled(X86_FEATURE_XENPV)) {
native_swapgs();
gsbase = rdgsbase();
native_swapgs();
@@ -190,7 +190,7 @@ static noinstr void __wrgsbase_inactive(unsigned long gsbase)
{
lockdep_assert_irqs_disabled();

- if (!static_cpu_has(X86_FEATURE_XENPV)) {
+ if (!cpu_feature_enabled(X86_FEATURE_XENPV)) {
native_swapgs();
wrgsbase(gsbase);
native_swapgs();
diff --git a/arch/x86/kernel/topology.c b/arch/x86/kernel/topology.c
index 8617d1ed9d31..1b83377274b8 100644
--- a/arch/x86/kernel/topology.c
+++ b/arch/x86/kernel/topology.c
@@ -106,7 +106,7 @@ int arch_register_cpu(int num)
* Xen PV guests don't support CPU0 hotplug at all.
*/
if (c->x86_vendor != X86_VENDOR_INTEL ||
- boot_cpu_has(X86_FEATURE_XENPV))
+ cpu_feature_enabled(X86_FEATURE_XENPV))
cpu0_hotpluggable = 0;

/*
--
2.35.3

2022-11-04 18:21:36

by Dave Hansen

Subject: Re: [PATCH v2 5/5] x86: switch to cpu_feature_enabled() for X86_FEATURE_XENPV

On 11/4/22 00:27, Juergen Gross wrote:
> Convert the remaining cases of static_cpu_has(X86_FEATURE_XENPV) and
> boot_cpu_has(X86_FEATURE_XENPV) to use cpu_feature_enabled(), allowing
> more efficient code in case the kernel is configured without
> CONFIG_XEN_PV.

As with the rest:

Acked-by: Dave Hansen <[email protected]>

Seems like a very straightforward, sane set of cleanups.

2022-11-22 18:17:03

by tip-bot2 for Alexey Makhalov

Subject: [tip: x86/cpu] x86/cpu: Switch to cpu_feature_enabled() for X86_FEATURE_XENPV

The following commit has been merged into the x86/cpu branch of tip:

Commit-ID: 6007878a782eb96f50a71c3a06cf3e931cf8aac1
Gitweb: https://git.kernel.org/tip/6007878a782eb96f50a71c3a06cf3e931cf8aac1
Author: Juergen Gross <[email protected]>
AuthorDate: Fri, 04 Nov 2022 08:27:01 +01:00
Committer: Borislav Petkov <[email protected]>
CommitterDate: Tue, 22 Nov 2022 16:18:19 +01:00

x86/cpu: Switch to cpu_feature_enabled() for X86_FEATURE_XENPV

Convert the remaining cases of static_cpu_has(X86_FEATURE_XENPV) and
boot_cpu_has(X86_FEATURE_XENPV) to use cpu_feature_enabled(), allowing
more efficient code in case the kernel is configured without
CONFIG_XEN_PV.

Signed-off-by: Juergen Gross <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Acked-by: Dave Hansen <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
---
arch/x86/kernel/cpu/amd.c | 2 +-
arch/x86/kernel/cpu/bugs.c | 2 +-
arch/x86/kernel/cpu/hygon.c | 2 +-
arch/x86/kernel/process_64.c | 4 ++--
arch/x86/kernel/topology.c | 2 +-
5 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 860b602..697fe88 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -985,7 +985,7 @@ static void init_amd(struct cpuinfo_x86 *c)
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))
+ if (!cpu_feature_enabled(X86_FEATURE_XENPV))
set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);

/*
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index e254f07..9e84b68 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -1302,7 +1302,7 @@ static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void)
return SPECTRE_V2_CMD_AUTO;
}

- if (cmd == SPECTRE_V2_CMD_IBRS && boot_cpu_has(X86_FEATURE_XENPV)) {
+ if (cmd == SPECTRE_V2_CMD_IBRS && cpu_feature_enabled(X86_FEATURE_XENPV)) {
pr_err("%s selected but running as XenPV guest. Switching to AUTO select\n",
mitigation_options[i].option);
return SPECTRE_V2_CMD_AUTO;
diff --git a/arch/x86/kernel/cpu/hygon.c b/arch/x86/kernel/cpu/hygon.c
index 21fd425..1c27645 100644
--- a/arch/x86/kernel/cpu/hygon.c
+++ b/arch/x86/kernel/cpu/hygon.c
@@ -339,7 +339,7 @@ static void init_hygon(struct cpuinfo_x86 *c)
set_cpu_cap(c, X86_FEATURE_ARAT);

/* Hygon CPUs don't reset SS attributes on SYSRET, Xen does. */
- if (!cpu_has(c, X86_FEATURE_XENPV))
+ if (!cpu_feature_enabled(X86_FEATURE_XENPV))
set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);

check_null_seg_clears_base(c);
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 6b3418b..e2f4691 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -165,7 +165,7 @@ static noinstr unsigned long __rdgsbase_inactive(void)

lockdep_assert_irqs_disabled();

- if (!static_cpu_has(X86_FEATURE_XENPV)) {
+ if (!cpu_feature_enabled(X86_FEATURE_XENPV)) {
native_swapgs();
gsbase = rdgsbase();
native_swapgs();
@@ -190,7 +190,7 @@ static noinstr void __wrgsbase_inactive(unsigned long gsbase)
{
lockdep_assert_irqs_disabled();

- if (!static_cpu_has(X86_FEATURE_XENPV)) {
+ if (!cpu_feature_enabled(X86_FEATURE_XENPV)) {
native_swapgs();
wrgsbase(gsbase);
native_swapgs();
diff --git a/arch/x86/kernel/topology.c b/arch/x86/kernel/topology.c
index 8617d1e..1b83377 100644
--- a/arch/x86/kernel/topology.c
+++ b/arch/x86/kernel/topology.c
@@ -106,7 +106,7 @@ int arch_register_cpu(int num)
* Xen PV guests don't support CPU0 hotplug at all.
*/
if (c->x86_vendor != X86_VENDOR_INTEL ||
- boot_cpu_has(X86_FEATURE_XENPV))
+ cpu_feature_enabled(X86_FEATURE_XENPV))
cpu0_hotpluggable = 0;

/*