| Message ID | 20240710160655.3402786-8-alexander.shishkin@linux.intel.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Enable Linear Address Space Separation support | expand |
On Wed, Jul 10, 2024 at 07:06:43PM +0300, Alexander Shishkin wrote: > In order to map the EFI runtime services, set_virtual_address_map > needs to be called, which resides in the lower half of the address > space. This means that LASS needs to be temporarily disabled around > this call. This can only be done before the CR pinning is set up. > > Move CR pinning setup behind the EFI initialization. > > Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> > Suggested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> So the previous patch makes us not boot, and this fixes it up? Perhaps order things differently? > --- > arch/x86/kernel/cpu/common.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c > index 8aa621dc7d30..c93c59a27dfa 100644 > --- a/arch/x86/kernel/cpu/common.c > +++ b/arch/x86/kernel/cpu/common.c > @@ -1948,7 +1948,6 @@ static __init void identify_boot_cpu(void) > enable_sep_cpu(); > #endif > cpu_detect_tlb(&boot_cpu_data); > - setup_cr_pinning(); > > tsx_init(); > tdx_init(); > @@ -2367,10 +2366,16 @@ void __init arch_cpu_finalize_init(void) > > /* > * This needs to follow the FPU initializtion, since EFI depends on it. > + * It also needs to precede the CR pinning setup, because we need to be > + * able to temporarily clear the CR4.LASS bit in order to execute the > + * set_virtual_address_map call, which resides in lower addresses and > + * would trip LASS if enabled. > */ > if (efi_enabled(EFI_RUNTIME_SERVICES)) > efi_enter_virtual_mode(); > > + setup_cr_pinning(); > + > /* > * Ensure that access to the per CPU representation has the initial > * boot CPU configuration. > -- > 2.43.0 >
On Thu, Jul 11, 2024 at 10:11:53AM +0200, Peter Zijlstra wrote: > On Wed, Jul 10, 2024 at 07:06:43PM +0300, Alexander Shishkin wrote: > > In order to map the EFI runtime services, set_virtual_address_map > > needs to be called, which resides in the lower half of the address > > space. This means that LASS needs to be temporarily disabled around > > this call. This can only be done before the CR pinning is set up. > > > > Move CR pinning setup behind the EFI initialization. > > > > Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> > > Suggested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > > So the previous patch makes us not boot, and this fixes it up? Perhaps > order things differently? Maybe just move LASS enabling (patch 04/16) to the very end of the patchset?
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 8aa621dc7d30..c93c59a27dfa 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1948,7 +1948,6 @@ static __init void identify_boot_cpu(void) enable_sep_cpu(); #endif cpu_detect_tlb(&boot_cpu_data); - setup_cr_pinning(); tsx_init(); tdx_init(); @@ -2367,10 +2366,16 @@ void __init arch_cpu_finalize_init(void) /* * This needs to follow the FPU initializtion, since EFI depends on it. + * It also needs to precede the CR pinning setup, because we need to be + * able to temporarily clear the CR4.LASS bit in order to execute the + * set_virtual_address_map call, which resides in lower addresses and + * would trip LASS if enabled. */ if (efi_enabled(EFI_RUNTIME_SERVICES)) efi_enter_virtual_mode(); + setup_cr_pinning(); + /* * Ensure that access to the per CPU representation has the initial * boot CPU configuration.
In order to map the EFI runtime services, set_virtual_address_map needs to be called, which resides in the lower half of the address space. This means that LASS needs to be temporarily disabled around this call. This can only be done before the CR pinning is set up. Move CR pinning setup behind the EFI initialization. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Suggested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> --- arch/x86/kernel/cpu/common.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)