accel/tcg: Add TCGCPUOps.tlb_fill_align

Add a new callback to handle softmmu paging.  Return the page
details directly, instead of passing them indirectly to
tlb_set_page.  Handle alignment simultaneously with paging so
that faults are handled with target-specific priority.

Route all calls of the two hooks through a tlb_fill_align
function local to cputlb.c.

As yet no targets implement the new hook.
As yet cputlb.c does not use the new alignment check.

Reviewed-by: Helge Deller <deller@gmx.de>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

include/hw/core/tcg-cpu-ops.h

@@ -13,6 +13,7 @@
 #include "exec/breakpoint.h"
 #include "exec/hwaddr.h"
 #include "exec/memattrs.h"
+#include "exec/memop.h"
 #include "exec/mmu-access-type.h"
 #include "exec/vaddr.h"
 
@@ -131,6 +132,31 @@ struct TCGCPUOps {
      * same function signature.
      */
     bool (*cpu_exec_halt)(CPUState *cpu);
+    /**
+     * @tlb_fill_align: Handle a softmmu tlb miss
+     * @cpu: cpu context
+     * @out: output page properties
+     * @addr: virtual address
+     * @access_type: read, write or execute
+     * @mmu_idx: mmu context
+     * @memop: memory operation for the access
+     * @size: memory access size, or 0 for whole page
+     * @probe: test only, no fault
+     * @ra: host return address for exception unwind
+     *
+     * If the access is valid, fill in @out and return true.
+     * Otherwise if probe is true, return false.
+     * Otherwise raise an exception and do not return.
+     *
+     * The alignment check for the access is deferred to this hook,
+     * so that the target can determine the priority of any alignment
+     * fault with respect to other potential faults from paging.
+     * Zero may be passed for @memop to skip any alignment check
+     * for non-memory-access operations such as probing.
+     */
+    bool (*tlb_fill_align)(CPUState *cpu, CPUTLBEntryFull *out, vaddr addr,
+                           MMUAccessType access_type, int mmu_idx,
+                           MemOp memop, int size, bool probe, uintptr_t ra);
     /**
      * @tlb_fill: Handle a softmmu tlb miss
      *