diff options
| author | H. Peter Anvin (Intel) <hpa@zytor.com> | 2023-12-05 02:50:06 -0800 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2024-01-31 22:01:36 +0100 |
| commit | 9356c4b8886c4f7d3436c3f7fe31715bdcf1c79e (patch) | |
| tree | 7003b89a1ee37481904e219a40639cc5733b3afc /arch/x86 | |
| parent | 65c9cc9e2c14602d98f1ca61c51ac954e9529303 (diff) | |
x86/fred: Update MSR_IA32_FRED_RSP0 during task switch
MSR_IA32_FRED_RSP0 is used during ring 3 event delivery, and needs to
be updated to point to the top of next task stack during task switch.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-18-xin3.li@intel.com
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/switch_to.h | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/x86/include/asm/switch_to.h b/arch/x86/include/asm/switch_to.h index f42dbf17f52b..c3bd0c0758c9 100644 --- a/arch/x86/include/asm/switch_to.h +++ b/arch/x86/include/asm/switch_to.h @@ -70,9 +70,13 @@ static inline void update_task_stack(struct task_struct *task) #ifdef CONFIG_X86_32 this_cpu_write(cpu_tss_rw.x86_tss.sp1, task->thread.sp0); #else - /* Xen PV enters the kernel on the thread stack. */ - if (cpu_feature_enabled(X86_FEATURE_XENPV)) + if (cpu_feature_enabled(X86_FEATURE_FRED)) { + /* WRMSRNS is a baseline feature for FRED. */ + wrmsrns(MSR_IA32_FRED_RSP0, (unsigned long)task_stack_page(task) + THREAD_SIZE); + } else if (cpu_feature_enabled(X86_FEATURE_XENPV)) { + /* Xen PV enters the kernel on the thread stack. */ load_sp0(task_top_of_stack(task)); + } #endif } |