Commit-ID: b9952ec78778aa7ae5b8df672668aece6fc93d2a Gitweb: https://git.kernel.org/tip/b9952ec78778aa7ae5b8df672668aece6fc93d2a Author: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> AuthorDate: Fri, 16 Feb 2018 14:49:46 +0300 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Wed, 21 Feb 2018 10:19:18 +0100 x86/xen: Allow XEN_PV and XEN_PVH to be enabled with X86_5LEVEL With boot-time switching between paging modes, XEN_PV and XEN_PVH can be boot into 4-level paging mode. Tested-by: Juergen Gross <jgross@xxxxxxxx> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Reviewed-by: Juergen Gross <jgross@xxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx> Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: linux-mm@xxxxxxxxx Link: http://lkml.kernel.org/r/20180216114948.68868-2-kirill.shutemov@xxxxxxxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- arch/x86/kernel/head_64.S | 12 ++++++------ arch/x86/xen/Kconfig | 5 ----- arch/x86/xen/mmu_pv.c | 21 +++++++++++++++++++++ 3 files changed, 27 insertions(+), 11 deletions(-) diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 145d7b9..3e9de0f 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -38,12 +38,12 @@ * */ +#define l4_index(x) (((x) >> 39) & 511) #define pud_index(x) (((x) >> PUD_SHIFT) & (PTRS_PER_PUD-1)) -#if defined(CONFIG_XEN_PV) || defined(CONFIG_XEN_PVH) -PGD_PAGE_OFFSET = pgd_index(__PAGE_OFFSET_BASE_L4) -PGD_START_KERNEL = pgd_index(__START_KERNEL_map) -#endif +L4_PAGE_OFFSET = l4_index(__PAGE_OFFSET_BASE_L4) +L4_START_KERNEL = l4_index(__START_KERNEL_map) + L3_START_KERNEL = pud_index(__START_KERNEL_map) .text @@ -386,9 +386,9 @@ NEXT_PAGE(early_dynamic_pgts) #if defined(CONFIG_XEN_PV) || defined(CONFIG_XEN_PVH) NEXT_PGD_PAGE(init_top_pgt) .quad level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC - .org init_top_pgt + PGD_PAGE_OFFSET*8, 0 + .org init_top_pgt + L4_PAGE_OFFSET*8, 0 .quad level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC - .org init_top_pgt + PGD_START_KERNEL*8, 0 + .org init_top_pgt + L4_START_KERNEL*8, 0 /* (2^48-(2*1024*1024*1024))/(2^39) = 511 */ .quad level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC .fill PTI_USER_PGD_FILL,8,0 diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig index f605825..c1f98f3 100644 --- a/arch/x86/xen/Kconfig +++ b/arch/x86/xen/Kconfig @@ -18,9 +18,6 @@ config XEN_PV bool "Xen PV guest support" default y depends on XEN - # XEN_PV is not ready to work with 5-level paging. - # Changes to hypervisor are also required. - depends on !X86_5LEVEL select XEN_HAVE_PVMMU select XEN_HAVE_VPMU help @@ -79,6 +76,4 @@ config XEN_DEBUG_FS config XEN_PVH bool "Support for running as a PVH guest" depends on XEN && XEN_PVHVM && ACPI - # Pre-built page tables are not ready to handle 5-level paging. - depends on !X86_5LEVEL def_bool n diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c index d850762..3f4fec5 100644 --- a/arch/x86/xen/mmu_pv.c +++ b/arch/x86/xen/mmu_pv.c @@ -538,6 +538,22 @@ static void xen_set_p4d(p4d_t *ptr, p4d_t val) xen_mc_issue(PARAVIRT_LAZY_MMU); } + +#if CONFIG_PGTABLE_LEVELS >= 5 +__visible p4dval_t xen_p4d_val(p4d_t p4d) +{ + return pte_mfn_to_pfn(p4d.p4d); +} +PV_CALLEE_SAVE_REGS_THUNK(xen_p4d_val); + +__visible p4d_t xen_make_p4d(p4dval_t p4d) +{ + p4d = pte_pfn_to_mfn(p4d); + + return native_make_p4d(p4d); +} +PV_CALLEE_SAVE_REGS_THUNK(xen_make_p4d); +#endif /* CONFIG_PGTABLE_LEVELS >= 5 */ #endif /* CONFIG_X86_64 */ static int xen_pmd_walk(struct mm_struct *mm, pmd_t *pmd, @@ -2411,6 +2427,11 @@ static const struct pv_mmu_ops xen_mmu_ops __initconst = { .alloc_pud = xen_alloc_pmd_init, .release_pud = xen_release_pmd_init, + +#if CONFIG_PGTABLE_LEVELS >= 5 + .p4d_val = PV_CALLEE_SAVE(xen_p4d_val), + .make_p4d = PV_CALLEE_SAVE(xen_make_p4d), +#endif #endif /* CONFIG_X86_64 */ .activate_mm = xen_activate_mm, -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html