[Qemu-devel] [PATCH] arm64: 64K pages and > 1024MB guest

* [Qemu-devel] [PATCH] arm64: 64K pages and > 1024MB guest
@ 2014-07-23 20:09 Joel Schopp
  2014-08-01 11:28 ` Peter Maydell
  0 siblings, 1 reply; 6+ messages in thread
From: Joel Schopp @ 2014-07-23 20:09 UTC (permalink / raw)
  To: qemu-devel; +Cc: Peter Maydell

kvm_set_phys_mem doesn't work on arm64 with memory > 1GB.  It exits with:
kvm_set_phys_mem: error registering slot: Invalid argument

An example of the failing address and size are start_addr == 0x90011000
and size=0xaffef000.  As you can see both of these are 4K aligned, not
64K aligned.

At 1024MB or smaller qemu only makes one call to kvm_set_user_memory_region,
so the start_addr and size are aligned by accident and the bug doesn't happen.

The following patch makes things work for me on an arm64 SOC.  I also smoke
tested the patch on an x86-64 box and qemu seemed to still run fine there
with the patch applied.

Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Joel Schopp <joel.schopp@amd.com>
---
 kvm-all.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kvm-all.c b/kvm-all.c
index 1402f4f..1975862 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -618,14 +618,14 @@ static void kvm_set_phys_mem(MemoryRegionSection *section, bool add)
 
     /* kvm works in page size chunks, but the function may be called
        with sub-page size and unaligned start address. */
-    delta = TARGET_PAGE_ALIGN(size) - size;
+    delta = HOST_PAGE_ALIGN(start_addr) - start_addr;
     if (delta > size) {
         return;
     }
     start_addr += delta;
     size -= delta;
-    size &= TARGET_PAGE_MASK;
-    if (!size || (start_addr & ~TARGET_PAGE_MASK)) {
+    size &= qemu_host_page_mask;
+    if (!size || (start_addr & ~qemu_host_page_mask)) {
         return;
     }
 

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