Thread (28 messages) 28 messages, 4 authors, 2022-06-29

Re: [PATCH v2 11/19] KVM: arm64: Move vcpu ON_UNSUPPORTED_CPU flag to the state flag set

From: Alexandru Elisei <hidden>
Date: 2022-06-15 13:15:10
Also in: kvm, kvmarm

Hi,

On Fri, Jun 10, 2022 at 10:28:30AM +0100, Marc Zyngier wrote:
quoted hunk ↗ jump to hunk
The ON_UNSUPPORTED_CPU flag is only there to track the sad fact
that we have ended-up on a CPU where we cannot really run.

Since this is only for the host kernel's use, move it to the state
set.

Reviewed-by: Fuad Tabba <redacted>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/include/asm/kvm_host.h | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 4f147bdc5ce9..0c22514cb7c7 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -519,6 +519,8 @@ struct kvm_vcpu_arch {
 #define HOST_SVE_ENABLED	__vcpu_single_flag(sflags, BIT(0))
 /* SME enabled for EL0 */
 #define HOST_SME_ENABLED	__vcpu_single_flag(sflags, BIT(1))
+/* Physical CPU not in supported_cpus */
+#define ON_UNSUPPORTED_CPU	__vcpu_single_flag(sflags, BIT(2))
I'm a bit confused here. The ON_UNSUPPORTED_CPU flag ends up in sflags. The
comment for sflags says:

+	/* State flags for kernel bookkeeping, unused by the hypervisor code */
+	u64 sflags;

The ON_UNSUPPORT_CPU flag is used exclusively by KVM (it's only used by the
file arch/arm64/kvm/arm.c), so why is it part of a set of flags which are
supposed to be unused by the hypervisor code?

Thanks,
Alex
quoted hunk ↗ jump to hunk
 
 /* Pointer to the vcpu's SVE FFR for sve_{save,load}_state() */
 #define vcpu_sve_pffr(vcpu) (kern_hyp_va((vcpu)->arch.sve_state) +	\
@@ -541,7 +543,6 @@ struct kvm_vcpu_arch {
 })
 
 /* vcpu_arch flags field values: */
-#define KVM_ARM64_ON_UNSUPPORTED_CPU	(1 << 15) /* Physical CPU not in supported_cpus */
 #define KVM_ARM64_WFIT			(1 << 17) /* WFIT instruction trapped */
 #define KVM_GUESTDBG_VALID_MASK (KVM_GUESTDBG_ENABLE | \
 				 KVM_GUESTDBG_USE_SW_BP | \
@@ -561,13 +562,13 @@ struct kvm_vcpu_arch {
 #endif
 
 #define vcpu_on_unsupported_cpu(vcpu)					\
-	((vcpu)->arch.flags & KVM_ARM64_ON_UNSUPPORTED_CPU)
+	vcpu_get_flag(vcpu, ON_UNSUPPORTED_CPU)
 
 #define vcpu_set_on_unsupported_cpu(vcpu)				\
-	((vcpu)->arch.flags |= KVM_ARM64_ON_UNSUPPORTED_CPU)
+	vcpu_set_flag(vcpu, ON_UNSUPPORTED_CPU)
 
 #define vcpu_clear_on_unsupported_cpu(vcpu)				\
-	((vcpu)->arch.flags &= ~KVM_ARM64_ON_UNSUPPORTED_CPU)
+	vcpu_clear_flag(vcpu, ON_UNSUPPORTED_CPU)
 
 #define vcpu_gp_regs(v)		(&(v)->arch.ctxt.regs)
 
-- 
2.34.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help