diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig index e7d05900efac..d88bfd66aaab 100644 --- a/arch/x86/xen/Kconfig +++ b/arch/x86/xen/Kconfig @@ -53,6 +53,6 @@ config XEN_DEBUG_FS config XEN_PVH bool "Support for running as a PVH guest" - depends on X86_64 && XEN && BROKEN + depends on X86_64 && XEN select XEN_PVHVM def_bool n diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S index 7faed5869e5b..485b69585540 100644 --- a/arch/x86/xen/xen-head.S +++ b/arch/x86/xen/xen-head.S @@ -11,8 +11,28 @@ #include #include +#include #include +#ifdef CONFIG_XEN_PVH +#define PVH_FEATURES_STR "|writable_descriptor_tables|auto_translated_physmap|supervisor_mode_kernel" +/* Note the lack of 'hvm_callback_vector'. Older hypervisor will + * balk at this being part of XEN_ELFNOTE_FEATURES, so we put it in + * XEN_ELFNOTE_SUPPORTED_FEATURES which older hypervisors will ignore. + */ +#define PVH_FEATURES ((1 << XENFEAT_writable_page_tables) | \ + (1 << XENFEAT_auto_translated_physmap) | \ + (1 << XENFEAT_supervisor_mode_kernel) | \ + (1 << XENFEAT_hvm_callback_vector)) +/* The XENFEAT_writable_page_tables is not stricly neccessary as we set that + * up regardless whether this CONFIG option is enabled or not, but it + * clarifies what the right flags need to be. + */ +#else +#define PVH_FEATURES_STR "" +#define PVH_FEATURES (0) +#endif + __INIT ENTRY(startup_xen) cld @@ -95,7 +115,10 @@ NEXT_HYPERCALL(arch_6) #endif ELFNOTE(Xen, XEN_ELFNOTE_ENTRY, _ASM_PTR startup_xen) ELFNOTE(Xen, XEN_ELFNOTE_HYPERCALL_PAGE, _ASM_PTR hypercall_page) - ELFNOTE(Xen, XEN_ELFNOTE_FEATURES, .asciz "!writable_page_tables|pae_pgdir_above_4gb") + ELFNOTE(Xen, XEN_ELFNOTE_FEATURES, .ascii "!writable_page_tables|pae_pgdir_above_4gb"; .asciz PVH_FEATURES_STR) + ELFNOTE(Xen, XEN_ELFNOTE_SUPPORTED_FEATURES, .long (PVH_FEATURES) | + (1 << XENFEAT_writable_page_tables) | + (1 << XENFEAT_dom0)) ELFNOTE(Xen, XEN_ELFNOTE_PAE_MODE, .asciz "yes") ELFNOTE(Xen, XEN_ELFNOTE_LOADER, .asciz "generic") ELFNOTE(Xen, XEN_ELFNOTE_L1_MFN_VALID, diff --git a/include/xen/interface/elfnote.h b/include/xen/interface/elfnote.h index 0360b15f4883..6f4eae328ca7 100644 --- a/include/xen/interface/elfnote.h +++ b/include/xen/interface/elfnote.h @@ -140,6 +140,19 @@ */ #define XEN_ELFNOTE_SUSPEND_CANCEL 14 +/* + * The features supported by this kernel (numeric). + * + * Other than XEN_ELFNOTE_FEATURES on pre-4.2 Xen, this note allows a + * kernel to specify support for features that older hypervisors don't + * know about. The set of features 4.2 and newer hypervisors will + * consider supported by the kernel is the combination of the sets + * specified through this and the string note. + * + * LEGACY: FEATURES + */ +#define XEN_ELFNOTE_SUPPORTED_FEATURES 17 + #endif /* __XEN_PUBLIC_ELFNOTE_H__ */ /*