KVM: Drop KVM_REQ_MMU_RELOAD and update vcpu-requests.rst documentation

Remove the now unused KVM_REQ_MMU_RELOAD, shift KVM_REQ_VM_DEAD into the
unoccupied space, and update vcpu-requests.rst, which was missing an
entry for KVM_REQ_VM_DEAD.  Switching KVM_REQ_VM_DEAD to entry '1' also
fixes the stale comment about bits 4-7 being reserved.
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Message-Id: <20220225182248.3812651-7-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Documentation/virt/kvm/vcpu-requests.rst

@@ -112,11 +112,10 @@ KVM_REQ_TLB_FLUSH
   choose to use the common kvm_flush_remote_tlbs() implementation will
   need to handle this VCPU request.
 
-KVM_REQ_MMU_RELOAD
+KVM_REQ_VM_DEAD
 
-  When shadow page tables are used and memory slots are removed it's
-  necessary to inform each VCPU to completely refresh the tables.  This
-  request is used for that.
+  This request informs all VCPUs that the VM is dead and unusable, e.g. due to
+  fatal error or because the VM's state has been intentionally destroyed.
 
 KVM_REQ_UNBLOCK
 

include/linux/kvm_host.h

@@ -153,10 +153,9 @@ static inline bool is_error_page(struct page *page)
  * Bits 4-7 are reserved for more arch-independent bits.
  */
 #define KVM_REQ_TLB_FLUSH         (0 | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
-#define KVM_REQ_MMU_RELOAD        (1 | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
+#define KVM_REQ_VM_DEAD           (1 | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
 #define KVM_REQ_UNBLOCK           2
 #define KVM_REQ_UNHALT            3
-#define KVM_REQ_VM_DEAD           (4 | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
 #define KVM_REQ_GPC_INVALIDATE    (5 | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
 #define KVM_REQUEST_ARCH_BASE     8