x86/xen: Rework the xen_{cpu,irq,mmu}_opsarrays

In order to allow objtool to make sense of all the various paravirt
functions, it needs to either parse whole pv_ops[] tables, or observe
individual assignments in the form:

  bf87:       48 c7 05 00 00 00 00 00 00 00 00        movq   $0x0,0x0(%rip)
    bf92 <xen_init_spinlocks+0x5f>
    bf8a: R_X86_64_PC32     pv_ops+0x268

As is, xen_cpu_ops[] is at offset +0 in pv_ops[] and could thus be
parsed as a 'normal' pv_ops[] table, however xen_irq_ops[] and
xen_mmu_ops[] are not.

Worse, both the latter two are compiled into the individual assignment
for by current GCC, but that's not something one can rely on.

Therefore, convert all three into full pv_ops[] tables. This has the
benefit of not needing to teach objtool about the offsets and
resulting in more conservative code-gen.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20210624095149.057262522@infradead.org

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 2b1a8ba7162901fd5ee6b12ce359eb100792dc16..6ed0af756950eb97ed2579d9fa4839934ea1fd5d 100644 (file)
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -1050,52 +1050,54 @@ static const struct pv_info xen_info __initconst = {
        .name = "Xen",
 };
 
-static const struct pv_cpu_ops xen_cpu_ops __initconst = {
-       .cpuid = xen_cpuid,
+static const typeof(pv_ops) xen_cpu_ops __initconst = {
+       .cpu = {
+               .cpuid = xen_cpuid,
 
-       .set_debugreg = xen_set_debugreg,
-       .get_debugreg = xen_get_debugreg,
+               .set_debugreg = xen_set_debugreg,
+               .get_debugreg = xen_get_debugreg,
 
-       .read_cr0 = xen_read_cr0,
-       .write_cr0 = xen_write_cr0,
+               .read_cr0 = xen_read_cr0,
+               .write_cr0 = xen_write_cr0,
 
-       .write_cr4 = xen_write_cr4,
+               .write_cr4 = xen_write_cr4,
 
-       .wbinvd = native_wbinvd,
+               .wbinvd = native_wbinvd,
 
-       .read_msr = xen_read_msr,
-       .write_msr = xen_write_msr,
+               .read_msr = xen_read_msr,
+               .write_msr = xen_write_msr,
 
-       .read_msr_safe = xen_read_msr_safe,
-       .write_msr_safe = xen_write_msr_safe,
+               .read_msr_safe = xen_read_msr_safe,
+               .write_msr_safe = xen_write_msr_safe,
 
-       .read_pmc = xen_read_pmc,
+               .read_pmc = xen_read_pmc,
 
-       .load_tr_desc = paravirt_nop,
-       .set_ldt = xen_set_ldt,
-       .load_gdt = xen_load_gdt,
-       .load_idt = xen_load_idt,
-       .load_tls = xen_load_tls,
-       .load_gs_index = xen_load_gs_index,
+               .load_tr_desc = paravirt_nop,
+               .set_ldt = xen_set_ldt,
+               .load_gdt = xen_load_gdt,
+               .load_idt = xen_load_idt,
+               .load_tls = xen_load_tls,
+               .load_gs_index = xen_load_gs_index,
 
-       .alloc_ldt = xen_alloc_ldt,
-       .free_ldt = xen_free_ldt,
+               .alloc_ldt = xen_alloc_ldt,
+               .free_ldt = xen_free_ldt,
 
-       .store_tr = xen_store_tr,
+               .store_tr = xen_store_tr,
 
-       .write_ldt_entry = xen_write_ldt_entry,
-       .write_gdt_entry = xen_write_gdt_entry,
-       .write_idt_entry = xen_write_idt_entry,
-       .load_sp0 = xen_load_sp0,
+               .write_ldt_entry = xen_write_ldt_entry,
+               .write_gdt_entry = xen_write_gdt_entry,
+               .write_idt_entry = xen_write_idt_entry,
+               .load_sp0 = xen_load_sp0,
 
 #ifdef CONFIG_X86_IOPL_IOPERM
-       .invalidate_io_bitmap = xen_invalidate_io_bitmap,
-       .update_io_bitmap = xen_update_io_bitmap,
+               .invalidate_io_bitmap = xen_invalidate_io_bitmap,
+               .update_io_bitmap = xen_update_io_bitmap,
 #endif
-       .io_delay = xen_io_delay,
+               .io_delay = xen_io_delay,
 
-       .start_context_switch = paravirt_start_context_switch,
-       .end_context_switch = xen_end_context_switch,
+               .start_context_switch = paravirt_start_context_switch,
+               .end_context_switch = xen_end_context_switch,
+       },
 };
 
 static void xen_restart(char *msg)
@@ -1231,7 +1233,7 @@ asmlinkage __visible void __init xen_start_kernel(void)
 
        /* Install Xen paravirt ops */
        pv_info = xen_info;
-       pv_ops.cpu = xen_cpu_ops;
+       pv_ops.cpu = xen_cpu_ops.cpu;
        paravirt_iret = xen_iret;
        xen_init_irq_ops();
 

diff --git a/arch/x86/xen/irq.c b/arch/x86/xen/irq.c
index 2f695b5125f886ab755c8ac86661fc99a319397b..4fe387e520af1261b25e6c1c59b41ac14042d4ab 100644 (file)
--- a/arch/x86/xen/irq.c
+++ b/arch/x86/xen/irq.c
@@ -94,17 +94,20 @@ static void xen_halt(void)
                xen_safe_halt();
 }
 
-static const struct pv_irq_ops xen_irq_ops __initconst = {
-       .save_fl = PV_CALLEE_SAVE(xen_save_fl),
-       .irq_disable = PV_CALLEE_SAVE(xen_irq_disable),
-       .irq_enable = PV_CALLEE_SAVE(xen_irq_enable),
+static const typeof(pv_ops) xen_irq_ops __initconst = {
+       .irq = {
 
-       .safe_halt = xen_safe_halt,
-       .halt = xen_halt,
+               .save_fl = PV_CALLEE_SAVE(xen_save_fl),
+               .irq_disable = PV_CALLEE_SAVE(xen_irq_disable),
+               .irq_enable = PV_CALLEE_SAVE(xen_irq_enable),
+
+               .safe_halt = xen_safe_halt,
+               .halt = xen_halt,
+       },
 };
 
 void __init xen_init_irq_ops(void)
 {
-       pv_ops.irq = xen_irq_ops;
+       pv_ops.irq = xen_irq_ops.irq;
        x86_init.irqs.intr_init = xen_init_IRQ;
 }

diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c
index f3cafe56fbe520f73ced054aa0d2ec17693501e5..b9a4f797ec1aa02c4f51ff97535766285b56b148 100644 (file)
--- a/arch/x86/xen/mmu_pv.c
+++ b/arch/x86/xen/mmu_pv.c
@@ -2076,67 +2076,69 @@ static void xen_leave_lazy_mmu(void)
        preempt_enable();
 }
 
-static const struct pv_mmu_ops xen_mmu_ops __initconst = {
-       .read_cr2 = __PV_IS_CALLEE_SAVE(xen_read_cr2),
-       .write_cr2 = xen_write_cr2,
+static const typeof(pv_ops) xen_mmu_ops __initconst = {
+       .mmu = {
+               .read_cr2 = __PV_IS_CALLEE_SAVE(xen_read_cr2),
+               .write_cr2 = xen_write_cr2,
 
-       .read_cr3 = xen_read_cr3,
-       .write_cr3 = xen_write_cr3_init,
+               .read_cr3 = xen_read_cr3,
+               .write_cr3 = xen_write_cr3_init,
 
-       .flush_tlb_user = xen_flush_tlb,
-       .flush_tlb_kernel = xen_flush_tlb,
-       .flush_tlb_one_user = xen_flush_tlb_one_user,
-       .flush_tlb_multi = xen_flush_tlb_multi,
-       .tlb_remove_table = tlb_remove_table,
+               .flush_tlb_user = xen_flush_tlb,
+               .flush_tlb_kernel = xen_flush_tlb,
+               .flush_tlb_one_user = xen_flush_tlb_one_user,
+               .flush_tlb_multi = xen_flush_tlb_multi,
+               .tlb_remove_table = tlb_remove_table,
 
-       .pgd_alloc = xen_pgd_alloc,
-       .pgd_free = xen_pgd_free,
+               .pgd_alloc = xen_pgd_alloc,
+               .pgd_free = xen_pgd_free,
 
-       .alloc_pte = xen_alloc_pte_init,
-       .release_pte = xen_release_pte_init,
-       .alloc_pmd = xen_alloc_pmd_init,
-       .release_pmd = xen_release_pmd_init,
+               .alloc_pte = xen_alloc_pte_init,
+               .release_pte = xen_release_pte_init,
+               .alloc_pmd = xen_alloc_pmd_init,
+               .release_pmd = xen_release_pmd_init,
 
-       .set_pte = xen_set_pte_init,
-       .set_pmd = xen_set_pmd_hyper,
+               .set_pte = xen_set_pte_init,
+               .set_pmd = xen_set_pmd_hyper,
 
-       .ptep_modify_prot_start = xen_ptep_modify_prot_start,
-       .ptep_modify_prot_commit = xen_ptep_modify_prot_commit,
+               .ptep_modify_prot_start = xen_ptep_modify_prot_start,
+               .ptep_modify_prot_commit = xen_ptep_modify_prot_commit,
 
-       .pte_val = PV_CALLEE_SAVE(xen_pte_val),
-       .pgd_val = PV_CALLEE_SAVE(xen_pgd_val),
+               .pte_val = PV_CALLEE_SAVE(xen_pte_val),
+               .pgd_val = PV_CALLEE_SAVE(xen_pgd_val),
 
-       .make_pte = PV_CALLEE_SAVE(xen_make_pte_init),
-       .make_pgd = PV_CALLEE_SAVE(xen_make_pgd),
+               .make_pte = PV_CALLEE_SAVE(xen_make_pte_init),
+               .make_pgd = PV_CALLEE_SAVE(xen_make_pgd),
 
-       .set_pud = xen_set_pud_hyper,
+               .set_pud = xen_set_pud_hyper,
 
-       .make_pmd = PV_CALLEE_SAVE(xen_make_pmd),
-       .pmd_val = PV_CALLEE_SAVE(xen_pmd_val),
+               .make_pmd = PV_CALLEE_SAVE(xen_make_pmd),
+               .pmd_val = PV_CALLEE_SAVE(xen_pmd_val),
 
-       .pud_val = PV_CALLEE_SAVE(xen_pud_val),
-       .make_pud = PV_CALLEE_SAVE(xen_make_pud),
-       .set_p4d = xen_set_p4d_hyper,
+               .pud_val = PV_CALLEE_SAVE(xen_pud_val),
+               .make_pud = PV_CALLEE_SAVE(xen_make_pud),
+               .set_p4d = xen_set_p4d_hyper,
 
-       .alloc_pud = xen_alloc_pmd_init,
-       .release_pud = xen_release_pmd_init,
+               .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),
+               .p4d_val = PV_CALLEE_SAVE(xen_p4d_val),
+               .make_p4d = PV_CALLEE_SAVE(xen_make_p4d),
 #endif
 
-       .activate_mm = xen_activate_mm,
-       .dup_mmap = xen_dup_mmap,
-       .exit_mmap = xen_exit_mmap,
+               .activate_mm = xen_activate_mm,
+               .dup_mmap = xen_dup_mmap,
+               .exit_mmap = xen_exit_mmap,
 
-       .lazy_mode = {
-               .enter = paravirt_enter_lazy_mmu,
-               .leave = xen_leave_lazy_mmu,
-               .flush = paravirt_flush_lazy_mmu,
-       },
+               .lazy_mode = {
+                       .enter = paravirt_enter_lazy_mmu,
+                       .leave = xen_leave_lazy_mmu,
+                       .flush = paravirt_flush_lazy_mmu,
+               },
 
-       .set_fixmap = xen_set_fixmap,
+               .set_fixmap = xen_set_fixmap,
+       },
 };
 
 void __init xen_init_mmu_ops(void)
@@ -2144,7 +2146,7 @@ void __init xen_init_mmu_ops(void)
        x86_init.paging.pagetable_init = xen_pagetable_init;
        x86_init.hyper.init_after_bootmem = xen_after_bootmem;
 
-       pv_ops.mmu = xen_mmu_ops;
+       pv_ops.mmu = xen_mmu_ops.mmu;
 
        memset(dummy_mapping, 0xff, PAGE_SIZE);
 }