[Qemu-arm] [RFC 0/1] arm: Setup EL1 and EL2 in AArch64 mode for 64bit Linux boots

[Qemu-arm] [RFC 0/1] arm: Setup EL1 and EL2 in AArch64 mode for 64bit Linux boots

[Edgar E. Iglesias]

From: "Edgar E. Iglesias" <edgar.iglesias@xilinx.com>

Hi,

I've seen some regressions in my test runs lately when enabling
EL2 and EL3. It turns out we are not setting RW when booting 64bit
Linux kernels.

In the long run, I'm not sure if this does the right thing, for
example we might need to revisit if we ever want to support direct
loading of 32bit kernels on an AArch64 core.
Anyway, this fixes my testruns for now.

Cheers,
Edgar

Edgar E. Iglesias (1):
  hw/arm: Setup EL1 and EL2 in AArch64 mode for 64bit Linux boots

 hw/arm/boot.c | 2 ++
 1 file changed, 2 insertions(+)

-- 
1.9.1

[Qemu-devel] [RFC 1/1] hw/arm: Setup EL1 and EL2 in AArch64 mode for 64bit Linux boots

[Edgar E. Iglesias]

From: "Edgar E. Iglesias" <edgar.iglesias@xilinx.com>

When booting Linux on AArch64 enabled cores, setup EL1 and
EL2 to use AArch64.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
---
 hw/arm/boot.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/hw/arm/boot.c b/hw/arm/boot.c
index 7742dd3..d05a998 100644
--- a/hw/arm/boot.c
+++ b/hw/arm/boot.c
@@ -488,7 +488,9 @@ static void do_cpu_reset(void *opaque)
                  * adjust.
                  */
                 if (env->aarch64) {
+                    env->cp15.scr_el3 |= SCR_RW;
                     if (arm_feature(env, ARM_FEATURE_EL2)) {
+                        env->cp15.hcr_el2 |= HCR_RW;
                         env->pstate = PSTATE_MODE_EL2h;
                     } else {
                         env->pstate = PSTATE_MODE_EL1h;
-- 
1.9.1

Re: [Qemu-devel] [RFC 0/1] arm: Setup EL1 and EL2 in AArch64 mode for 64bit Linux boots

[Peter Maydell]

On 27 January 2016 at 23:42, Edgar E. Iglesias <edgar.iglesias@gmail.com> wrote:
> From: "Edgar E. Iglesias" <edgar.iglesias@xilinx.com>
>
> Hi,
>
> I've seen some regressions in my test runs lately when enabling
> EL2 and EL3. It turns out we are not setting RW when booting 64bit
> Linux kernels.
>
> In the long run, I'm not sure if this does the right thing, for
> example we might need to revisit if we ever want to support direct
> loading of 32bit kernels on an AArch64 core.
> Anyway, this fixes my testruns for now.

Looks like the right thing to me. Applied to target-arm.next, thanks.

-- PMM