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| author | Peter Zijlstra <peterz@infradead.org> | 2022-03-08 18:30:22 +0300 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2022-03-15 12:32:34 +0300 |
| commit | 8b87d8cec1b31ea710568ae49ba5f5146318da0d (patch) | |
| tree | d66a56f82b2e643c95e46710bdbe69064ef32178 /arch/x86/xen | |
| parent | 6cf3e4c0d29102c74aca1ce0c1710be9d02e440e (diff) | |
| download | linux-8b87d8cec1b31ea710568ae49ba5f5146318da0d.tar.xz | |
x86/entry,xen: Early rewrite of restore_regs_and_return_to_kernel()
By doing an early rewrite of 'jmp native_iret` in
restore_regs_and_return_to_kernel() we can get rid of the last
INTERRUPT_RETURN user and paravirt_iret.
Suggested-by: Andrew Cooper <Andrew.Cooper3@citrix.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154317.815039833@infradead.org
Diffstat (limited to 'arch/x86/xen')
| -rw-r--r-- | arch/x86/xen/enlighten_pv.c | 7 | ||||
| -rw-r--r-- | arch/x86/xen/xen-asm.S | 1 |
2 files changed, 7 insertions, 1 deletions
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c index d47c3d176ae4..3c7a55c43f13 100644 --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -1177,6 +1177,8 @@ static void __init xen_domu_set_legacy_features(void) x86_platform.legacy.rtc = 0; } +extern void early_xen_iret_patch(void); + /* First C function to be called on Xen boot */ asmlinkage __visible void __init xen_start_kernel(void) { @@ -1187,6 +1189,10 @@ asmlinkage __visible void __init xen_start_kernel(void) if (!xen_start_info) return; + __text_gen_insn(&early_xen_iret_patch, + JMP32_INSN_OPCODE, &early_xen_iret_patch, &xen_iret, + JMP32_INSN_SIZE); + xen_domain_type = XEN_PV_DOMAIN; xen_start_flags = xen_start_info->flags; @@ -1195,7 +1201,6 @@ asmlinkage __visible void __init xen_start_kernel(void) /* Install Xen paravirt ops */ pv_info = xen_info; pv_ops.cpu = xen_cpu_ops.cpu; - paravirt_iret = xen_iret; xen_init_irq_ops(); /* diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S index e730e6200e64..ee17b94e3fc0 100644 --- a/arch/x86/xen/xen-asm.S +++ b/arch/x86/xen/xen-asm.S @@ -189,6 +189,7 @@ hypercall_iret = hypercall_page + __HYPERVISOR_iret * 32 */ SYM_CODE_START(xen_iret) UNWIND_HINT_EMPTY + ANNOTATE_NOENDBR pushq $0 jmp hypercall_iret SYM_CODE_END(xen_iret) |