Commit 80675b3a authored by Tom Lendacky's avatar Tom Lendacky Committed by Paolo Bonzini
Browse files

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: default avatarTom Lendacky <thomas.lendacky@amd.com>
Message-Id: <d7aed505e31e3954268b2015bb60a1486269c780.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 85ca8be9

arch/x86/kvm/svm/sev.c

+14 −11
Original line number Diff line number Diff line
@@ -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;