It would be tempting to turn the 'pause' state into a flag.

However, this cannot easily be done as it is updated out of context,
while all the flags expect to only be updated from the vcpu thread.
Turning it into a flag would require to make all flag updates
atomic, which isn't necessary desireable.

Document this, and take this opportunity to move the field next
to the flag sets, filling a hole in the vcpu structure.

Signed-off-by: Marc Zyngier <m...@kernel.org>
---
 arch/arm64/include/asm/kvm_host.h | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h 
b/arch/arm64/include/asm/kvm_host.h
index 83f3dae4333a..8c47b7f8ef92 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -344,6 +344,15 @@ struct kvm_vcpu_arch {
        /* State flags, unused by the hypervisor code */
        u8 sflags;
 
+       /*
+        * Don't run the guest (internal implementation need).
+        *
+        * Contrary to the flags above, this is set/cleared outside of
+        * a vcpu context, and thus cannot be mixed with the flags
+        * themselves (or the flag accesses need to be made atomic).
+        */
+       bool pause;
+
        /*
         * We maintain more than a single set of debug registers to support
         * debugging the guest from the host and to maintain separate host and
@@ -397,9 +406,6 @@ struct kvm_vcpu_arch {
        /* vcpu power state */
        struct kvm_mp_state mp_state;
 
-       /* Don't run the guest (internal implementation need) */
-       bool pause;
-
        /* Cache some mmu pages needed inside spinlock regions */
        struct kvm_mmu_memory_cache mmu_page_cache;
 
-- 
2.34.1

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