KVM: SVM: Update ASID allocation to support SEV-ES guests

SEV and SEV-ES guests each have dedicated ASID ranges. Update the ASID
allocation routine to return an ASID in the respective range.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <d7aed505e31e3954268b2015bb60a1486269c780.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 0e922741023bc9fbaeff6123eec39cf890e32f92..b81d12f1bd37e2462224569f3e28a279ce5f8a17 100644 (file)
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -61,19 +61,19 @@ static int sev_flush_asids(void)
 }
 
 /* Must be called with the sev_bitmap_lock held */
-static bool __sev_recycle_asids(void)
+static bool __sev_recycle_asids(int min_asid, int max_asid)
 {
        int pos;
 
        /* Check if there are any ASIDs to reclaim before performing a flush */
-       pos = find_next_bit(sev_reclaim_asid_bitmap,
-                           max_sev_asid, min_sev_asid - 1);
-       if (pos >= max_sev_asid)
+       pos = find_next_bit(sev_reclaim_asid_bitmap, max_sev_asid, min_asid);
+       if (pos >= max_asid)
                return false;
 
        if (sev_flush_asids())
                return false;
 
+       /* The flush process will flush all reclaimable SEV and SEV-ES ASIDs */
        bitmap_xor(sev_asid_bitmap, sev_asid_bitmap, sev_reclaim_asid_bitmap,
                   max_sev_asid);
        bitmap_zero(sev_reclaim_asid_bitmap, max_sev_asid);
@@ -81,20 +81,23 @@ static bool __sev_recycle_asids(void)
        return true;
 }
 
-static int sev_asid_new(void)
+static int sev_asid_new(struct kvm_sev_info *sev)
 {
+       int pos, min_asid, max_asid;
        bool retry = true;
-       int pos;
 
        mutex_lock(&sev_bitmap_lock);
 
        /*
-        * SEV-enabled guest must use asid from min_sev_asid to max_sev_asid.
+        * SEV-enabled guests must use asid from min_sev_asid to max_sev_asid.
+        * SEV-ES-enabled guest can use from 1 to min_sev_asid - 1.
         */
+       min_asid = sev->es_active ? 0 : min_sev_asid - 1;
+       max_asid = sev->es_active ? min_sev_asid - 1 : max_sev_asid;
 again:
-       pos = find_next_zero_bit(sev_asid_bitmap, max_sev_asid, min_sev_asid - 1);
-       if (pos >= max_sev_asid) {
-               if (retry && __sev_recycle_asids()) {
+       pos = find_next_zero_bit(sev_asid_bitmap, max_sev_asid, min_asid);
+       if (pos >= max_asid) {
+               if (retry && __sev_recycle_asids(min_asid, max_asid)) {
                        retry = false;
                        goto again;
                }
@@ -176,7 +179,7 @@ static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
        if (unlikely(sev->active))
                return ret;
 
-       asid = sev_asid_new();
+       asid = sev_asid_new(sev);
        if (asid < 0)
                return ret;