The types p2m_is_readonly() checks for aren't applicable to PV;
specifically get_gfn() won't ever return any such type for PV domains.
Extend the HVM-conditional block of code, also past the subsequent HVM-
only if(). This way the "emulate_readonly" also becomes unreachable when
!HVM, so move the conditional there upwards as well. Noticing the
earlier shadow_mode_refcounts() check, move it up even further, right
after that check. With that, the "done" label also needs marking as
potentially unused.
Signed-off-by: Jan Beulich
---
v2: Parts split off to a subsequent patch.
--- a/xen/arch/x86/mm/shadow/multi.c
+++ b/xen/arch/x86/mm/shadow/multi.c
@@ -2613,8 +2613,6 @@ static int cf_check sh_page_fault(
? EXCRET_fault_fixed : 0;
}
-#endif /* CONFIG_HVM */
-
/* Ignore attempts to write to read-only memory. */
if ( p2m_is_readonly(p2mt) && (ft == ft_demand_write) )
goto emulate_readonly; /* skip over the instruction */
@@ -2633,12 +2631,14 @@ static int cf_check sh_page_fault(
goto emulate;
}
+#endif /* CONFIG_HVM */
+
perfc_incr(shadow_fault_fixed);
d->arch.paging.log_dirty.fault_count++;
sh_reset_early_unshadow(v);
trace_shadow_fixup(gw.l1e, va);
- done:
+ done: __maybe_unused;
sh_audit_gw(v, );
SHADOW_PRINTK("fixed\n");
shadow_audit_tables(v);
@@ -2650,6 +2650,7 @@ static int cf_check sh_page_fault(
if ( !shadow_mode_refcounts(d) || !guest_mode(regs) )
goto not_a_shadow_fault;
+#ifdef CONFIG_HVM
/*
* We do not emulate user writes. Instead we use them as a hint that the
* page is no longer a page table. This behaviour differs from native, but
@@ -2677,7 +2678,6 @@ static int cf_check sh_page_fault(
goto not_a_shadow_fault;
}
-#ifdef CONFIG_HVM
/* Unshadow if we are writing to a toplevel pagetable that is
* flagged as a dying process, and that is not currently used. */
if ( sh_mfn_is_a_page_table(gmfn) && is_hvm_domain(d) &&
