KVM: PPC: Remove kvmppc_claim_lpid

Removing kvmppc_claim_lpid makes the lpid allocator API a bit simpler to
change the underlying implementation in a future patch.

The host LPID is always 0, so that can be a detail of the allocator. If
the allocator range is restricted, that can reserve LPIDs at the top of
the range. This allows kvmppc_claim_lpid to be removed.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220123120043.3586018-2-npiggin@gmail.com

diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 838d4cb460b7edf6b9a820a509e763e63298b0fe..55ff0d88b20a07b09e17e0787024bdc3666d39a8 100644 (file)
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -877,7 +877,6 @@ int kvm_vcpu_ioctl_dirty_tlb(struct kvm_vcpu *vcpu,
                             struct kvm_dirty_tlb *cfg);
 
 long kvmppc_alloc_lpid(void);
-void kvmppc_claim_lpid(long lpid);
 void kvmppc_free_lpid(long lpid);
 void kvmppc_init_lpid(unsigned long nr_lpids);
 

diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index 0aeb51738ca9b2d8e0966c291a3d6b19bf84d87a..fed4b7652a95fe35e68c4cf9105d0e2bc4936bb1 100644 (file)
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -256,14 +256,15 @@ void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot,
 
 int kvmppc_mmu_hv_init(void)
 {
-       unsigned long host_lpid, rsvd_lpid;
+       unsigned long rsvd_lpid;
 
        if (!mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE))
                return -EINVAL;
 
-       host_lpid = 0;
-       if (cpu_has_feature(CPU_FTR_HVMODE))
-               host_lpid = mfspr(SPRN_LPID);
+       if (cpu_has_feature(CPU_FTR_HVMODE)) {
+               if (WARN_ON(mfspr(SPRN_LPID) != 0))
+                       return -EINVAL;
+       }
 
        /* POWER8 and above have 12-bit LPIDs (10-bit in POWER7) */
        if (cpu_has_feature(CPU_FTR_ARCH_207S))
@@ -271,11 +272,8 @@ int kvmppc_mmu_hv_init(void)
        else
                rsvd_lpid = LPID_RSVD_POWER7;
 
-       kvmppc_init_lpid(rsvd_lpid + 1);
-
-       kvmppc_claim_lpid(host_lpid);
        /* rsvd_lpid is reserved for use in partition switching */
-       kvmppc_claim_lpid(rsvd_lpid);
+       kvmppc_init_lpid(rsvd_lpid);
 
        return 0;
 }

diff --git a/arch/powerpc/kvm/e500mc.c b/arch/powerpc/kvm/e500mc.c
index fa0d8dbbe48411c28703e0577518ed984ad96d66..2b9ad8984ea13d095b56fc6ed3ef02825a21978b 100644 (file)
--- a/arch/powerpc/kvm/e500mc.c
+++ b/arch/powerpc/kvm/e500mc.c
@@ -399,7 +399,6 @@ static int __init kvmppc_e500mc_init(void)
         * allocator.
         */
        kvmppc_init_lpid(KVMPPC_NR_LPIDS/threads_per_core);
-       kvmppc_claim_lpid(0); /* host */
 
        r = kvm_init(NULL, sizeof(struct kvmppc_vcpu_e500), 0, THIS_MODULE);
        if (r)

diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 875c30c12db046957bed254f5519a279023e2e8e..1a0e3ede891fe2463cd8466738c32a17f0a61154 100644 (file)
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -2515,12 +2515,6 @@ long kvmppc_alloc_lpid(void)
 }
 EXPORT_SYMBOL_GPL(kvmppc_alloc_lpid);
 
-void kvmppc_claim_lpid(long lpid)
-{
-       set_bit(lpid, lpid_inuse);
-}
-EXPORT_SYMBOL_GPL(kvmppc_claim_lpid);
-
 void kvmppc_free_lpid(long lpid)
 {
        clear_bit(lpid, lpid_inuse);
@@ -2531,6 +2525,7 @@ void kvmppc_init_lpid(unsigned long nr_lpids_param)
 {
        nr_lpids = min_t(unsigned long, KVMPPC_NR_LPIDS, nr_lpids_param);
        memset(lpid_inuse, 0, sizeof(lpid_inuse));
+       set_bit(0, lpid_inuse); /* The host LPID must always be 0 */
 }
 EXPORT_SYMBOL_GPL(kvmppc_init_lpid);