On 2020-07-02 16:37, Suzuki K Poulose wrote:
Hi Marc
On 07/01/2020 04:42 PM, Marc Zyngier wrote:
On 2020-07-01 15:20, Suzuki K Poulose wrote:
When the host doesn't support 32bit guests, the kvmtool fails
without a proper message on what is wrong. i.e,
$ lkvm run -c 1 Image --aarch32
# lkvm run -k Image -m 256 -c 1 --name guest-105618
Fatal: Unable to initialise vcpu
Given that there is no other easy way to check if the host supports
32bit
guests, it is always good to report this by checking the capability,
rather
than leaving the users to hunt this down by looking at the code!
After this patch:
$ lkvm run -c 1 Image --aarch32
# lkvm run -k Image -m 256 -c 1 --name guest-105695
Fatal: 32bit guests are not supported
Fancy!
Cc: Will Deacon <will@xxxxxxxxxx>
Reported-by: Sami Mujawar <sami.mujawar@xxxxxxx>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
---
arm/kvm-cpu.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arm/kvm-cpu.c b/arm/kvm-cpu.c
index 554414f..2acecae 100644
--- a/arm/kvm-cpu.c
+++ b/arm/kvm-cpu.c
@@ -46,6 +46,10 @@ struct kvm_cpu *kvm_cpu__arch_init(struct kvm
*kvm,
unsigned long cpu_id)
.features = ARM_VCPU_FEATURE_FLAGS(kvm, cpu_id)
};
+ if (kvm->cfg.arch.aarch32_guest &&
+ !kvm__supports_extension(kvm, KVM_CAP_ARM_EL1_32BIT))
Can you please check that this still compiles for 32bit host?
Yes, it does. I have built this on an arm32 rootfs with make ARCH=arm.
The kvm->cfg.arch is common across arm/arm64 and is defined here :
arm/include/arm-common/kvm-config-arch.h
I was worried about the availability of KVM_CAP_ARM_EL1_32BIT,
but being a capability, it is common to all arches. It is
KVM_ARM_VCPU_EL1_32BIT that is 32bit only, but that's not what
you are using. Too many flags! ;-)
Thanks,
M.
--
Jazz is not dead. It just smells funny...
