From: Claudio Imbrenda <imbrenda@linux.ibm.com>
To: kvm@vger.kernel.org
Cc: cohuck@redhat.com, borntraeger@de.ibm.com, frankja@linux.ibm.com,
thuth@redhat.com, pasic@linux.ibm.com, david@redhat.com,
linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2 05/13] KVM: s390: pv: handle secure storage exceptions for normal guests
Date: Wed, 28 Jul 2021 16:26:23 +0200 [thread overview]
Message-ID: <20210728142631.41860-6-imbrenda@linux.ibm.com> (raw)
In-Reply-To: <20210728142631.41860-1-imbrenda@linux.ibm.com>
With upcoming patches, normal guests might touch secure pages.
This patch extends the existing exception handler to convert the pages
to non secure also when the exception is triggered by a normal guest.
This can happen for example when a secure guest reboots; the first
stage of a secure guest is non secure, and in general a secure guest
can reboot into non-secure mode.
If the secure memory of the previous boot has not been cleared up
completely yet, a non-secure guest might touch secure memory, which
will need to be handled properly.
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
arch/s390/mm/fault.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index eb68b4f36927..b89d625ea2ec 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -767,6 +767,7 @@ void do_secure_storage_access(struct pt_regs *regs)
struct vm_area_struct *vma;
struct mm_struct *mm;
struct page *page;
+ struct gmap *gmap;
int rc;
/*
@@ -796,6 +797,16 @@ void do_secure_storage_access(struct pt_regs *regs)
}
switch (get_fault_type(regs)) {
+ case GMAP_FAULT:
+ gmap = (struct gmap *)S390_lowcore.gmap;
+ /*
+ * Very unlikely, but if it happens, simply try again.
+ * The next attempt will trigger a different exception.
+ */
+ addr = __gmap_translate(gmap, addr);
+ if (addr == -EFAULT)
+ break;
+ fallthrough;
case USER_FAULT:
mm = current->mm;
mmap_read_lock(mm);
@@ -824,7 +835,6 @@ void do_secure_storage_access(struct pt_regs *regs)
if (rc)
BUG();
break;
- case GMAP_FAULT:
default:
do_fault_error(regs, VM_READ | VM_WRITE, VM_FAULT_BADMAP);
WARN_ON_ONCE(1);
--
2.31.1
next prev parent reply other threads:[~2021-07-28 14:28 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-28 14:26 [PATCH v2 00/13] KVM: s390: pv: implement lazy destroy Claudio Imbrenda
2021-07-28 14:26 ` [PATCH v2 01/13] KVM: s390: pv: avoid stall notifications for some UVCs Claudio Imbrenda
2021-07-29 9:58 ` Janosch Frank
2021-07-29 12:52 ` Claudio Imbrenda
2021-07-29 10:49 ` Cornelia Huck
2021-07-29 13:22 ` Claudio Imbrenda
2021-07-28 14:26 ` [PATCH v2 02/13] KVM: s390: pv: leak the ASCE page when destroy fails Claudio Imbrenda
2021-07-29 10:41 ` Janosch Frank
2021-07-29 12:54 ` Claudio Imbrenda
2021-07-29 13:45 ` Janosch Frank
2021-07-28 14:26 ` [PATCH v2 03/13] KVM: s390: pv: properly handle page flags for protected guests Claudio Imbrenda
2021-07-29 11:43 ` Janosch Frank
2021-07-28 14:26 ` [PATCH v2 04/13] KVM: s390: pv: handle secure storage violations " Claudio Imbrenda
2021-07-28 14:26 ` Claudio Imbrenda [this message]
2021-07-29 12:17 ` [PATCH v2 05/13] KVM: s390: pv: handle secure storage exceptions for normal guests Janosch Frank
2021-07-29 13:28 ` Claudio Imbrenda
2021-07-28 14:26 ` [PATCH v2 06/13] KVM: s390: pv: refactor s390_reset_acc Claudio Imbrenda
2021-07-28 14:26 ` [PATCH v2 07/13] KVM: s390: pv: usage counter instead of flag Claudio Imbrenda
2021-07-28 14:26 ` [PATCH v2 08/13] KVM: s390: pv: add export before import Claudio Imbrenda
2021-07-28 14:26 ` [PATCH v2 09/13] KVM: s390: pv: lazy destroy for reboot Claudio Imbrenda
2021-07-28 14:26 ` [PATCH v2 10/13] KVM: s390: pv: extend lazy destroy to handle shutdown Claudio Imbrenda
2021-07-28 14:26 ` [PATCH v2 11/13] KVM: s390: pv: module parameter to fence lazy destroy Claudio Imbrenda
2021-07-28 14:26 ` [PATCH v2 12/13] KVM: s390: pv: add OOM notifier for " Claudio Imbrenda
2021-07-28 14:26 ` [PATCH v2 13/13] KVM: s390: pv: add support for UV feature bits Claudio Imbrenda
2021-07-29 9:52 ` Janosch Frank
2021-07-29 13:28 ` Claudio Imbrenda
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