From: "tip-bot2 for Andy Lutomirski" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Andy Lutomirski <luto@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>, x86 <x86@kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: [tip: x86/fsgsbase] x86/fsgsbase: Fix Xen PV support
Date: Wed, 01 Jul 2020 13:33:15 -0000 [thread overview]
Message-ID: <159361039503.4006.17824211510339513520.tip-bot2@tip-bot2> (raw)
In-Reply-To: <f07c08f178fe9711915862b656722a207cd52c28.1593192140.git.luto@kernel.org>
The following commit has been merged into the x86/fsgsbase branch of tip:
Commit-ID: d029bff60aa6c7eab281d52602b6a7a971615324
Gitweb: https://git.kernel.org/tip/d029bff60aa6c7eab281d52602b6a7a971615324
Author: Andy Lutomirski <luto@kernel.org>
AuthorDate: Fri, 26 Jun 2020 10:24:30 -07:00
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Wed, 01 Jul 2020 15:27:20 +02:00
x86/fsgsbase: Fix Xen PV support
On Xen PV, SWAPGS doesn't work. Teach __rdfsbase_inactive() and
__wrgsbase_inactive() to use rdmsrl()/wrmsrl() on Xen PV. The Xen
pvop code will understand this and issue the correct hypercalls.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/f07c08f178fe9711915862b656722a207cd52c28.1593192140.git.luto@kernel.org
---
arch/x86/kernel/process_64.c | 24 ++++++++++++++++++------
1 file changed, 18 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index cb8e37d..e14476f 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -163,9 +163,15 @@ static noinstr unsigned long __rdgsbase_inactive(void)
lockdep_assert_irqs_disabled();
- native_swapgs();
- gsbase = rdgsbase();
- native_swapgs();
+ if (!static_cpu_has(X86_FEATURE_XENPV)) {
+ native_swapgs();
+ gsbase = rdgsbase();
+ native_swapgs();
+ } else {
+ instrumentation_begin();
+ rdmsrl(MSR_KERNEL_GS_BASE, gsbase);
+ instrumentation_end();
+ }
return gsbase;
}
@@ -182,9 +188,15 @@ static noinstr void __wrgsbase_inactive(unsigned long gsbase)
{
lockdep_assert_irqs_disabled();
- native_swapgs();
- wrgsbase(gsbase);
- native_swapgs();
+ if (!static_cpu_has(X86_FEATURE_XENPV)) {
+ native_swapgs();
+ wrgsbase(gsbase);
+ native_swapgs();
+ } else {
+ instrumentation_begin();
+ wrmsrl(MSR_KERNEL_GS_BASE, gsbase);
+ instrumentation_end();
+ }
}
/*
prev parent reply other threads:[~2020-07-01 13:33 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-26 17:24 [PATCH fsgsbase v2 0/4] x86/fsgsbase: Some fixes Andy Lutomirski
2020-06-26 17:24 ` [PATCH fsgsbase v2 1/4] selftests/x86/fsgsbase: Fix a comment in the ptrace_write_gsbase test Andy Lutomirski
2020-07-01 13:33 ` [tip: x86/fsgsbase] " tip-bot2 for Andy Lutomirski
2020-06-26 17:24 ` [PATCH fsgsbase v2 2/4] selftests/x86/fsgsbase: Add a missing memory constraint Andy Lutomirski
2020-07-01 13:33 ` [tip: x86/fsgsbase] " tip-bot2 for Andy Lutomirski
2020-06-26 17:24 ` [PATCH fsgsbase v2 3/4] x86/ptrace: Fix 32-bit PTRACE_SETREGS vs fsbase and gsbase Andy Lutomirski
2020-07-01 13:33 ` [tip: x86/fsgsbase] " tip-bot2 for Andy Lutomirski
2020-06-26 17:24 ` [PATCH fsgsbase v2 4/4] x86/fsgsbase: Fix Xen PV support Andy Lutomirski
2020-06-29 5:17 ` Jürgen Groß
2020-06-29 11:07 ` Andrew Cooper
2020-07-01 13:33 ` tip-bot2 for Andy Lutomirski [this message]
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