lkml.org 
[lkml]   [2020]   [Sep]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[RFC PATCH 31/35] KVM: SVM: Update ASID allocation to support SEV-ES guests
Date
From: Tom Lendacky <thomas.lendacky@amd.com>

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>
---
arch/x86/kvm/svm/sev.c | 25 ++++++++++++++-----------
1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 15be71b30e2a..73d2a3f6c83c 100644
--- 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;

--
2.28.0
\
 
 \ /
  Last update: 2020-09-14 22:27    [W:0.505 / U:0.484 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site