Messages in this thread Patch in this message | | | From | Lai Jiangshan <> | Date | Sat, 20 Nov 2021 09:23:14 +0800 | Subject | Re: [PATCH] x86/paravirt: Fix build PARAVIRT_XXL=y without XEN_PV |
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On Fri, Nov 19, 2021 at 6:20 PM Kirill A. Shutemov <kirill@shutemov.name> wrote:
> > It is part of what CONFIG_PARAVIRT_XXL was designed for to enable > > pv-aware INTERRUPT_RETURN. > > That's very vague statement. > > Could you elaborate on what is wrong with proposed fix? >
Although CONFIG_PARAVIRT_XXL is enabled only when XEN, but they are separated configs. There is no wrong with the patch, but it is not justified to narrow the scope of INTERRUPT_RETURN.
How about:
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index cebec95a7124..4459f853f77b 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -746,10 +746,16 @@ extern void default_banner(void); #define PARA_SITE(ptype, ops) _PVSITE(ptype, ops, .quad, 8) #define PARA_INDIRECT(addr) *addr(%rip)
+#ifdef CONFIG_XEN_PV +#define XEN_IRET "jmp xen_iret;" +#else +#define XEN_IRET "" +#endif + #define INTERRUPT_RETURN \ ANNOTATE_RETPOLINE_SAFE; \ ALTERNATIVE_TERNARY("jmp *paravirt_iret(%rip);", \ - X86_FEATURE_XENPV, "jmp xen_iret;", "jmp native_iret;") + X86_FEATURE_XENPV, XEN_IRET, "jmp native_iret;")
#ifdef CONFIG_DEBUG_ENTRY .macro PARA_IRQ_save_fl And in the patch, INTERRUPT_RETURN is moved at the definition of SWAPGS, but SWAPGS is going to be removed:
https://lore.kernel.org/lkml/20211026143436.19071-2-jiangshanlai@gmail.com/
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