diff options
| author | Sean Christopherson <seanjc@google.com> | 2023-07-21 13:18:41 -0700 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2023-08-03 15:37:14 -0700 |
| commit | b23c83ad2c638420ec0608a9de354507c41bec29 (patch) | |
| tree | 0b0778d125d3736404f549553574a2f52a42a4a4 /arch/x86/kernel/crash.c | |
| parent | 41e90a69a49be2e3467e811ae8fdc17456af1b02 (diff) | |
| download | linux-b23c83ad2c638420ec0608a9de354507c41bec29.tar.gz linux-b23c83ad2c638420ec0608a9de354507c41bec29.tar.bz2 linux-b23c83ad2c638420ec0608a9de354507c41bec29.zip | |
x86/reboot: VMCLEAR active VMCSes before emergency reboot
VMCLEAR active VMCSes before any emergency reboot, not just if the kernel
may kexec into a new kernel after a crash. Per Intel's SDM, the VMX
architecture doesn't require the CPU to flush the VMCS cache on INIT. If
an emergency reboot doesn't RESET CPUs, cached VMCSes could theoretically
be kept and only be written back to memory after the new kernel is booted,
i.e. could effectively corrupt memory after reboot.
Opportunistically remove the setting of the global pointer to NULL to make
checkpatch happy.
Cc: Andrew Cooper <Andrew.Cooper3@citrix.com>
Link: https://lore.kernel.org/r/20230721201859.2307736-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'arch/x86/kernel/crash.c')
| -rw-r--r-- | arch/x86/kernel/crash.c | 31 |
1 files changed, 0 insertions, 31 deletions
diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c index cdd92ab43cda..54cd959cb316 100644 --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c @@ -48,27 +48,6 @@ struct crash_memmap_data { unsigned int type; }; -/* - * This is used to VMCLEAR all VMCSs loaded on the - * processor. And when loading kvm_intel module, the - * callback function pointer will be assigned. - * - * protected by rcu. - */ -crash_vmclear_fn __rcu *crash_vmclear_loaded_vmcss = NULL; -EXPORT_SYMBOL_GPL(crash_vmclear_loaded_vmcss); - -static inline void cpu_crash_vmclear_loaded_vmcss(void) -{ - crash_vmclear_fn *do_vmclear_operation = NULL; - - rcu_read_lock(); - do_vmclear_operation = rcu_dereference(crash_vmclear_loaded_vmcss); - if (do_vmclear_operation) - do_vmclear_operation(); - rcu_read_unlock(); -} - #if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC) static void kdump_nmi_callback(int cpu, struct pt_regs *regs) @@ -76,11 +55,6 @@ static void kdump_nmi_callback(int cpu, struct pt_regs *regs) crash_save_cpu(regs, cpu); /* - * VMCLEAR VMCSs loaded on all cpus if needed. - */ - cpu_crash_vmclear_loaded_vmcss(); - - /* * Disable Intel PT to stop its logging */ cpu_emergency_stop_pt(); @@ -133,11 +107,6 @@ void native_machine_crash_shutdown(struct pt_regs *regs) crash_smp_send_stop(); - /* - * VMCLEAR VMCSs loaded on this cpu if needed. - */ - cpu_crash_vmclear_loaded_vmcss(); - cpu_emergency_disable_virtualization(); /* |