Linux Virtualization - Apr 2020 - [PATCH 1/3] target/mips: Support variable page size

Traditionally, MIPS use 4KB page size, but Loongson prefer 16KB page
size in system emulator. So, let's define TARGET_PAGE_BITS_VARY and
TARGET_PAGE_BITS_MIN to support variable page size.

Cc: Jiaxun Yang <jiaxun.yang at flygoat.com>
Signed-off-by: Huacai Chen <chenhc at lemote.com>
---
 target/mips/cpu-param.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/target/mips/cpu-param.h b/target/mips/cpu-param.h
index 308660d..9c4a6ea 100644
--- a/target/mips/cpu-param.h
+++ b/target/mips/cpu-param.h
@@ -23,7 +23,12 @@
 #  define TARGET_VIRT_ADDR_SPACE_BITS 32
 #endif
 #endif
+#ifdef CONFIG_USER_ONLY
 #define TARGET_PAGE_BITS 12
+#else
+#define TARGET_PAGE_BITS_VARY
+#define TARGET_PAGE_BITS_MIN 12
+#endif
 #define NB_MMU_MODES 4
 
 #endif
-- 
2.7.0

Loongson processor prefers 16KB page size in system emulator, so let's
define mc->minimum_page_bits to 14.

Cc: Jiaxun Yang <jiaxun.yang at flygoat.com>
Signed-off-by: Huacai Chen <chenhc at lemote.com>
---
 hw/mips/mips_fulong2e.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/mips/mips_fulong2e.c b/hw/mips/mips_fulong2e.c
index 5040afd..23897d7 100644
--- a/hw/mips/mips_fulong2e.c
+++ b/hw/mips/mips_fulong2e.c
@@ -399,6 +399,7 @@ static void mips_fulong2e_machine_init(MachineClass *mc)
     mc->default_cpu_type = MIPS_CPU_TYPE_NAME("Loongson-2E");
     mc->default_ram_size = 256 * MiB;
     mc->default_ram_id = "fulong2e.ram";
+    mc->minimum_page_bits = 14;
 }
 
 DEFINE_MACHINE("fulong2e", mips_fulong2e_machine_init)
-- 
2.7.0

I submitted the MIPS/fulong2e support about ten years ago, and after
that I became a MIPS kernel developer. Last year, Philippe Mathieu-
Daud? asked me that whether I can be a reviewer of MIPS/fulong2e, and I
promised that I will do some QEMU work in the next year (i.e., 2020 and
later). I think now (and also in future) I can have some spare time, so
I can finally do some real work on QEMU/MIPS. And if possible, I hope I
can be a co-maintainer of MIPS/fulong2e.

Cc: Jiaxun Yang <jiaxun.yang at flygoat.com>
Signed-off-by: Huacai Chen <chenhc at lemote.com>
---
 MAINTAINERS | 1 +
 1 file changed, 1 insertion(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 642c8e0..3281ff2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1073,6 +1073,7 @@ F: hw/mips/mips_r4k.c
 Fulong 2E
 M: Philippe Mathieu-Daud? <f4bug at amsat.org>
 M: Aleksandar Markovic <aleksandar.qemu.devel at gmail.com>
+M: Huacai Chen <chenhc at lemote.com>
 S: Odd Fixes
 F: hw/mips/mips_fulong2e.c
 F: hw/isa/vt82c686.c
-- 
2.7.0