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

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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>
This commit is contained in:
Tom Lendacky 2020-12-10 11:10:05 -06:00 committed by Paolo Bonzini
parent 85ca8be938
commit 80675b3ad4
1 changed files with 14 additions and 11 deletions
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25
arch/x86/kvm/svm/sev.c
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@ -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;