From: Xiaoyao Li <xiaoyao.li@intel.com>
To: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
hpa@zytor.com, Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <sean.j.christopherson@intel.com>,
Andy Lutomirski <luto@kernel.org>,
tony.luck@intel.com
Cc: peterz@infradead.org, fenghua.yu@intel.com,
Arvind Sankar <nivedita@alum.mit.edu>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Jim Mattson <jmattson@google.com>,
x86@kernel.org, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org, Xiaoyao Li <xiaoyao.li@intel.com>
Subject: [PATCH v4 04/10] x86/split_lock: Export handle_user_split_lock()
Date: Sat, 14 Mar 2020 15:34:08 +0800 [thread overview]
Message-ID: <20200314073414.184213-5-xiaoyao.li@intel.com> (raw)
In-Reply-To: <20200314073414.184213-1-xiaoyao.li@intel.com>
In the future, KVM will use handle_user_split_lock() to handle #AC
caused by split lock in guest. Due to the fact that KVM doesn't have
a @regs context and will pre-check EFLASG.AC, move the EFLAGS.AC check
to do_alignment_check().
Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
---
arch/x86/include/asm/cpu.h | 4 ++--
arch/x86/kernel/cpu/intel.c | 7 ++++---
arch/x86/kernel/traps.c | 2 +-
3 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h
index ff6f3ca649b3..ff567afa6ee1 100644
--- a/arch/x86/include/asm/cpu.h
+++ b/arch/x86/include/asm/cpu.h
@@ -43,11 +43,11 @@ unsigned int x86_stepping(unsigned int sig);
#ifdef CONFIG_CPU_SUP_INTEL
extern void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c);
extern void switch_to_sld(unsigned long tifn);
-extern bool handle_user_split_lock(struct pt_regs *regs, long error_code);
+extern bool handle_user_split_lock(unsigned long ip);
#else
static inline void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c) {}
static inline void switch_to_sld(unsigned long tifn) {}
-static inline bool handle_user_split_lock(struct pt_regs *regs, long error_code)
+static inline bool handle_user_split_lock(unsigned long ip)
{
return false;
}
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 3eeab717a0d0..c401d174c8db 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -1102,13 +1102,13 @@ static void split_lock_init(struct cpuinfo_x86 *c)
sld_state = sld_disable;
}
-bool handle_user_split_lock(struct pt_regs *regs, long error_code)
+bool handle_user_split_lock(unsigned long ip)
{
- if ((regs->flags & X86_EFLAGS_AC) || sld_state == sld_fatal)
+ if (sld_state == sld_fatal)
return false;
pr_warn_ratelimited("#AC: %s/%d took a split_lock trap at address: 0x%lx\n",
- current->comm, current->pid, regs->ip);
+ current->comm, current->pid, ip);
/*
* Disable the split lock detection for this task so it can make
@@ -1119,6 +1119,7 @@ bool handle_user_split_lock(struct pt_regs *regs, long error_code)
set_tsk_thread_flag(current, TIF_SLD);
return true;
}
+EXPORT_SYMBOL_GPL(handle_user_split_lock);
/*
* This function is called only when switching between tasks with
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 0ef5befaed7d..407ff9be610f 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -304,7 +304,7 @@ dotraplinkage void do_alignment_check(struct pt_regs *regs, long error_code)
local_irq_enable();
- if (handle_user_split_lock(regs, error_code))
+ if (!(regs->flags & X86_EFLAGS_AC) && handle_user_split_lock(regs->ip))
return;
do_trap(X86_TRAP_AC, SIGBUS, "alignment check", regs,
--
2.20.1
next prev parent reply other threads:[~2020-03-15 2:14 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-14 7:34 [PATCH v4 00/10] x86/split_lock: Add feature split lock detection support in kvm Xiaoyao Li
2020-03-14 7:34 ` [PATCH v4 01/10] x86/split_lock: Rework the initialization flow of split lock detection Xiaoyao Li
2020-03-14 7:34 ` [PATCH v4 02/10] x86/split_lock: Avoid runtime reads of the TEST_CTRL MSR Xiaoyao Li
2020-03-14 7:34 ` [PATCH v4 03/10] x86/split_lock: Re-define the kernel param option for split_lock_detect Xiaoyao Li
2020-03-14 7:34 ` Xiaoyao Li [this message]
2020-03-14 7:34 ` [PATCH v4 05/10] x86/split_lock: Add and export several functions for KVM Xiaoyao Li
2020-03-14 7:34 ` [PATCH v4 06/10] kvm: x86: Emulate split-lock access as a write Xiaoyao Li
2020-03-14 7:34 ` [PATCH v4 07/10] kvm: vmx: Extend VMX's #AC interceptor to handle split lock #AC happens in guest Xiaoyao Li
2020-03-14 7:34 ` [PATCH v4 08/10] kvm: x86: Emulate MSR IA32_CORE_CAPABILITIES Xiaoyao Li
2020-03-14 7:34 ` [PATCH v4 09/10] kvm: vmx: Enable MSR_TEST_CTRL for intel guest Xiaoyao Li
2020-03-14 7:34 ` [PATCH v4 10/10] x86: vmx: virtualize split lock detection Xiaoyao Li
2020-03-15 2:56 ` Xiaoyao Li
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