| Message ID | 20200211135256.24617-31-joro@8bytes.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Linux as SEV-ES Guest Support | expand |
On Tue, Feb 11, 2020 at 5:53 AM Joerg Roedel <joro@8bytes.org> wrote: > > From: Joerg Roedel <jroedel@suse.de> > > Move the assembly coded dispatch between page-faults and all other > exceptions to C code to make it easier to maintain and extend. > > Signed-off-by: Joerg Roedel <jroedel@suse.de> > --- > arch/x86/kernel/head64.c | 20 ++++++++++++++++++++ > arch/x86/kernel/head_64.S | 11 +---------- > 2 files changed, 21 insertions(+), 10 deletions(-) > > diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c > index 7cdfb7113811..d83c62ebaa85 100644 > --- a/arch/x86/kernel/head64.c > +++ b/arch/x86/kernel/head64.c > @@ -36,6 +36,8 @@ > #include <asm/microcode.h> > #include <asm/kasan.h> > #include <asm/fixmap.h> > +#include <asm/extable.h> > +#include <asm/trap_defs.h> > > /* > * Manage page tables very early on. > @@ -377,6 +379,24 @@ int __init early_make_pgtable(unsigned long address) > return __early_make_pgtable(address, pmd); > } > > +void __init early_exception(struct pt_regs *regs, int trapnr) > +{ > + unsigned long cr2; > + int r; How about int (or bool) handled; Or just if (!early_make_pgtable) return; This would also be nicer if you inverted the return value so that true means "I handled it". --Andy
On Tue, Feb 11, 2020 at 02:44:45PM -0800, Andy Lutomirski wrote: > How about int (or bool) handled; Or just if (!early_make_pgtable) > return; This would also be nicer if you inverted the return value so > that true means "I handled it". Okay, makes sense. Changed the return value of early_make_pgtable() to bool and this function to: void __init early_exception(struct pt_regs *regs, int trapnr) { if (trapnr == X86_TRAP_PF && early_make_pgtable(native_read_cr2())) return; early_fixup_exception(regs, trapnr); } Regards, Joerg
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 7cdfb7113811..d83c62ebaa85 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -36,6 +36,8 @@ #include <asm/microcode.h> #include <asm/kasan.h> #include <asm/fixmap.h> +#include <asm/extable.h> +#include <asm/trap_defs.h> /* * Manage page tables very early on. @@ -377,6 +379,24 @@ int __init early_make_pgtable(unsigned long address) return __early_make_pgtable(address, pmd); } +void __init early_exception(struct pt_regs *regs, int trapnr) +{ + unsigned long cr2; + int r; + + switch (trapnr) { + case X86_TRAP_PF: + cr2 = native_read_cr2(); + r = early_make_pgtable(cr2); + break; + default: + r = 1; + } + + if (r) + early_fixup_exception(regs, trapnr); +} + /* Don't add a printk in there. printk relies on the PDA which is not initialized yet. */ static void __init clear_bss(void) diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 0af79f783659..81cf6c5763ef 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -357,18 +357,9 @@ SYM_CODE_START_LOCAL(early_idt_handler_common) pushq %r15 /* pt_regs->r15 */ UNWIND_HINT_REGS - cmpq $14,%rsi /* Page fault? */ - jnz 10f - GET_CR2_INTO(%rdi) /* can clobber %rax if pv */ - call early_make_pgtable - andl %eax,%eax - jz 20f /* All good */ - -10: movq %rsp,%rdi /* RDI = pt_regs; RSI is already trapnr */ - call early_fixup_exception + call early_exception -20: decl early_recursion_flag(%rip) jmp restore_regs_and_return_to_kernel SYM_CODE_END(early_idt_handler_common)