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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,
	Ulrich.Weigand@de.ibm.com
Subject: [PATCH v3 06/14] KVM: s390: pv: handle secure storage exceptions for normal guests
Date: Wed,  4 Aug 2021 17:40:38 +0200	[thread overview]
Message-ID: <20210804154046.88552-7-imbrenda@linux.ibm.com> (raw)
In-Reply-To: <20210804154046.88552-1-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 | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index eb68b4f36927..74784581f42d 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 +797,14 @@ void do_secure_storage_access(struct pt_regs *regs)
 	}
 
 	switch (get_fault_type(regs)) {
+	case GMAP_FAULT:
+		gmap = (struct gmap *)S390_lowcore.gmap;
+		addr = __gmap_translate(gmap, addr);
+		if (IS_ERR_VALUE(addr)) {
+			do_fault_error(regs, VM_ACCESS_FLAGS, VM_FAULT_BADMAP);
+			break;
+		}
+		fallthrough;
 	case USER_FAULT:
 		mm = current->mm;
 		mmap_read_lock(mm);
@@ -824,7 +833,6 @@ 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


  parent reply	other threads:[~2021-08-04 15:41 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-04 15:40 [PATCH v3 00/14] KVM: s390: pv: implement lazy destroy Claudio Imbrenda
2021-08-04 15:40 ` [PATCH v3 01/14] KVM: s390: pv: add macros for UVC CC values Claudio Imbrenda
2021-08-06  7:26   ` David Hildenbrand
2021-08-06  9:34     ` Claudio Imbrenda
2021-08-06 15:15     ` Janosch Frank
2021-08-04 15:40 ` [PATCH v3 02/14] KVM: s390: pv: avoid stall notifications for some UVCs Claudio Imbrenda
2021-08-06  7:30   ` David Hildenbrand
2021-08-06  9:33     ` Claudio Imbrenda
2021-08-04 15:40 ` [PATCH v3 03/14] KVM: s390: pv: leak the ASCE page when destroy fails Claudio Imbrenda
2021-08-06  7:31   ` David Hildenbrand
2021-08-06  9:32     ` Claudio Imbrenda
2021-08-06 11:39       ` David Hildenbrand
2021-08-04 15:40 ` [PATCH v3 04/14] KVM: s390: pv: properly handle page flags for protected guests Claudio Imbrenda
2021-08-04 15:40 ` [PATCH v3 05/14] KVM: s390: pv: handle secure storage violations " Claudio Imbrenda
2021-08-04 15:40 ` Claudio Imbrenda [this message]
2021-08-04 15:40 ` [PATCH v3 07/14] KVM: s390: pv: refactor s390_reset_acc Claudio Imbrenda
2021-08-04 15:40 ` [PATCH v3 08/14] KVM: s390: pv: usage counter instead of flag Claudio Imbrenda
2021-08-04 15:40 ` [PATCH v3 09/14] KVM: s390: pv: add export before import Claudio Imbrenda
2021-08-04 15:40 ` [PATCH v3 10/14] KVM: s390: pv: lazy destroy for reboot Claudio Imbrenda
2021-08-04 15:40 ` [PATCH v3 11/14] KVM: s390: pv: extend lazy destroy to handle shutdown Claudio Imbrenda
2021-08-04 15:40 ` [PATCH v3 12/14] KVM: s390: pv: module parameter to fence lazy destroy Claudio Imbrenda
2021-08-04 15:40 ` [PATCH v3 13/14] KVM: s390: pv: add OOM notifier for " Claudio Imbrenda
2021-08-04 15:40 ` [PATCH v3 14/14] KVM: s390: pv: avoid export before import if possible Claudio Imbrenda
2021-08-06  7:10 ` [PATCH v3 00/14] KVM: s390: pv: implement lazy destroy David Hildenbrand
2021-08-06  9:30   ` Claudio Imbrenda
2021-08-06 11:30     ` David Hildenbrand
2021-08-06 13:44       ` Claudio Imbrenda
2021-08-09  8:50         ` David Hildenbrand

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