[PATCH for-5.1] acpi-pm-tmr: allow 2-byte reads

[Michael Tokarev]

As found in LP#964247, MacOS Catalina performs 2-byte reads
on the acpi timer address space while the spec says it should
be 4-byte. Allow 2-byte reads.

Reported-By: Simon John <git@the-jedi.co.uk>
Signed-Off-By: Michael Tokarev <mjt@tls.msk.ru>
---
 hw/acpi/core.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

I'm applying this to debian qemu package, need the fix
faster in order to release security updates for other
branches.

diff --git a/hw/acpi/core.c b/hw/acpi/core.c
index 45cbed49ab..9be38aa2ac 100644
--- a/hw/acpi/core.c
+++ b/hw/acpi/core.c
@@ -530,7 +530,9 @@ static void acpi_pm_tmr_write(void *opaque, hwaddr addr, 
uint64_t val,
 static const MemoryRegionOps acpi_pm_tmr_ops = {
     .read = acpi_pm_tmr_read,
     .write = acpi_pm_tmr_write,
-    .valid.min_access_size = 4,
+    .impl.min_access_size = 4,
+     /* at least MacOS Catalina reads 2 bytes and fails if it doesn't work */
+    .valid.min_access_size = 2,
     .valid.max_access_size = 4,
     .endianness = DEVICE_LITTLE_ENDIAN,
 };
-- 
2.20.1