Hi Oliver,
On 3/24/22 12:31 AM, Oliver Upton wrote:
On Wed, Mar 23, 2022 at 08:46:40PM +0800, Gavin Shan wrote:
On 3/23/22 2:04 AM, Oliver Upton wrote:
On Tue, Mar 22, 2022 at 04:06:51PM +0800, Gavin Shan wrote:
This supports SDEI_VERSION hypercall by returning v1.1, which is
the specification version we're following. The vendor is set to
'KVM'.
Signed-off-by: Gavin Shan <gshan@xxxxxxxxxx>
---
arch/arm64/kvm/sdei.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/arch/arm64/kvm/sdei.c b/arch/arm64/kvm/sdei.c
index 8a9b477b8977..5a3a64cd6e84 100644
--- a/arch/arm64/kvm/sdei.c
+++ b/arch/arm64/kvm/sdei.c
@@ -118,6 +118,14 @@ static bool remove_all_vcpu_events(struct kvm_vcpu *vcpu,
return pending;
}
+static unsigned long hypercall_version(struct kvm_vcpu *vcpu)
+{
+ /* v1.1 and the vendor is KVM */
+ return (1UL << SDEI_VERSION_MAJOR_SHIFT) |
+ (1UL << SDEI_VERSION_MINOR_SHIFT) |
+ 0x4b564d;
It looks like the SDEI specification states that the vendor-defined
version number is 32 bits. Could we just use one of the
ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_{0,3} values instead?
ASCII 'KVM' is neat, but in reality guest software will just throw it in
a macro regardless. Might as well use one of the values we've already
trained it to use :-)
Also, it would appear that guest discovery of SDEI relies upon KVM
reporting a valid SDEI version. IMO, this patch should come at the very
end when KVM actually implements SDEI.
Yeah, I was sticky to the pattern of "KVM". However, I think it's good
to reuse the existing one. Lets use ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_2
if you agree. Its first two characters are "VM" at least.
Sounds fine to me. The only other nit I'd say is we should define a
macro for it too, something like:
#define KVM_SDEI_VENDOR ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_2
Agreed, and the macro will be put into arch/arm64/include/asm/kvm_sdei.h.
arch/arm64/include/uapi/asm/kvm_sdei_state.h isn't the right place because
the dependent macro ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_2 isn't exposed by
ABI.
Thanks,
Gavin
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