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From: Christian Borntraeger <borntraeger@de.ibm.com>
To: Christian Borntraeger <borntraeger@de.ibm.com>,
	Janosch Frank <frankja@linux.vnet.ibm.com>
Cc: KVM <kvm@vger.kernel.org>, Cornelia Huck <cohuck@redhat.com>,
	David Hildenbrand <david@redhat.com>,
	Thomas Huth <thuth@redhat.com>,
	Ulrich Weigand <Ulrich.Weigand@de.ibm.com>,
	Claudio Imbrenda <imbrenda@linux.ibm.com>,
	linux-s390 <linux-s390@vger.kernel.org>,
	Michael Mueller <mimu@linux.ibm.com>,
	Vasily Gorbik <gor@linux.ibm.com>,
	Janosch Frank <frankja@linux.ibm.com>
Subject: [PATCH v2 20/42] KVM: S390: protvirt: Introduce instruction data area bounce buffer
Date: Fri, 14 Feb 2020 17:26:36 -0500
Message-ID: <20200214222658.12946-21-borntraeger@de.ibm.com> (raw)
In-Reply-To: <20200214222658.12946-1-borntraeger@de.ibm.com>

From: Janosch Frank <frankja@linux.ibm.com>

Now that we can't access guest memory anymore, we have a dedicated
satellite block that's a bounce buffer for instruction data.

We re-use the memop interface to copy the instruction data to / from
userspace. This lets us re-use a lot of QEMU code which used that
interface to make logical guest memory accesses which are not possible
anymore in protected mode anyway.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
[borntraeger@de.ibm.com: patch merging, splitting, fixing]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
 arch/s390/include/asm/kvm_host.h | 11 ++++++++-
 arch/s390/kvm/kvm-s390.c         | 42 ++++++++++++++++++++++++++++++++
 arch/s390/kvm/pv.c               |  9 +++++++
 include/uapi/linux/kvm.h         |  6 ++++-
 4 files changed, 66 insertions(+), 2 deletions(-)

diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 4fcbb055a565..aa945b101fff 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -127,6 +127,12 @@ struct mcck_volatile_info {
 #define CR14_INITIAL_MASK (CR14_UNUSED_32 | CR14_UNUSED_33 | \
 			   CR14_EXTERNAL_DAMAGE_SUBMASK)
 
+#define SIDAD_SIZE_MASK		0xff
+#define sida_origin(sie_block) \
+	((sie_block)->sidad & PAGE_MASK)
+#define sida_size(sie_block) \
+	((((sie_block)->sidad & SIDAD_SIZE_MASK) + 1) * PAGE_SIZE)
+
 #define CPUSTAT_STOPPED    0x80000000
 #define CPUSTAT_WAIT       0x10000000
 #define CPUSTAT_ECALL_PEND 0x08000000
@@ -315,7 +321,10 @@ struct kvm_s390_sie_block {
 #define CRYCB_FORMAT2 0x00000003
 	__u32	crycbd;			/* 0x00fc */
 	__u64	gcr[16];		/* 0x0100 */
-	__u64	gbea;			/* 0x0180 */
+	union {
+		__u64	gbea;		/* 0x0180 */
+		__u64	sidad;
+	};
 	__u8    reserved188[8];		/* 0x0188 */
 	__u64   sdnxo;			/* 0x0190 */
 	__u8    reserved198[8];		/* 0x0198 */
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 6ebb0dae5a2e..8db82aaf1275 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -4435,6 +4435,34 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
 	return r;
 }
 
+static long kvm_s390_guest_sida_op(struct kvm_vcpu *vcpu,
+				   struct kvm_s390_mem_op *mop)
+{
+	void __user *uaddr = (void __user *)mop->buf;
+	int r = 0;
+
+	if (mop->flags || !mop->size)
+		return -EINVAL;
+	if (mop->size + mop->sida_offset < mop->size)
+		return -EINVAL;
+	if (mop->size + mop->sida_offset > sida_size(vcpu->arch.sie_block))
+		return -E2BIG;
+
+	switch (mop->op) {
+	case KVM_S390_MEMOP_SIDA_READ:
+		if (copy_to_user(uaddr, (void *)(sida_origin(vcpu->arch.sie_block) +
+				 mop->sida_offset), mop->size))
+			r = -EFAULT;
+
+		break;
+	case KVM_S390_MEMOP_SIDA_WRITE:
+		if (copy_from_user((void *)(sida_origin(vcpu->arch.sie_block) +
+				   mop->sida_offset), uaddr, mop->size))
+			r = -EFAULT;
+		break;
+	}
+	return r;
+}
 static long kvm_s390_guest_mem_op(struct kvm_vcpu *vcpu,
 				  struct kvm_s390_mem_op *mop)
 {
@@ -4444,6 +4472,7 @@ static long kvm_s390_guest_mem_op(struct kvm_vcpu *vcpu,
 	const u64 supported_flags = KVM_S390_MEMOP_F_INJECT_EXCEPTION
 				    | KVM_S390_MEMOP_F_CHECK_ONLY;
 
+	BUILD_BUG_ON(sizeof(*mop) != 64);
 	if (mop->flags & ~supported_flags || mop->ar >= NUM_ACRS || !mop->size)
 		return -EINVAL;
 
@@ -4460,6 +4489,10 @@ static long kvm_s390_guest_mem_op(struct kvm_vcpu *vcpu,
 
 	switch (mop->op) {
 	case KVM_S390_MEMOP_LOGICAL_READ:
+		if (kvm_s390_pv_is_protected(vcpu->kvm)) {
+			r = -EINVAL;
+			break;
+		}
 		if (mop->flags & KVM_S390_MEMOP_F_CHECK_ONLY) {
 			r = check_gva_range(vcpu, mop->gaddr, mop->ar,
 					    mop->size, GACC_FETCH);
@@ -4472,6 +4505,10 @@ static long kvm_s390_guest_mem_op(struct kvm_vcpu *vcpu,
 		}
 		break;
 	case KVM_S390_MEMOP_LOGICAL_WRITE:
+		if (kvm_s390_pv_is_protected(vcpu->kvm)) {
+			r = -EINVAL;
+			break;
+		}
 		if (mop->flags & KVM_S390_MEMOP_F_CHECK_ONLY) {
 			r = check_gva_range(vcpu, mop->gaddr, mop->ar,
 					    mop->size, GACC_STORE);
@@ -4483,6 +4520,11 @@ static long kvm_s390_guest_mem_op(struct kvm_vcpu *vcpu,
 		}
 		r = write_guest(vcpu, mop->gaddr, mop->ar, tmpbuf, mop->size);
 		break;
+	case KVM_S390_MEMOP_SIDA_READ:
+	case KVM_S390_MEMOP_SIDA_WRITE:
+		/* we are locked against sida going away by the vcpu->mutex */
+		r = kvm_s390_guest_sida_op(vcpu, mop);
+		break;
 	default:
 		r = -EINVAL;
 	}
diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c
index 09573e36c329..80169a9b43ec 100644
--- a/arch/s390/kvm/pv.c
+++ b/arch/s390/kvm/pv.c
@@ -92,6 +92,7 @@ int kvm_s390_pv_destroy_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc)
 
 	free_pages(vcpu->arch.pv.stor_base,
 		   get_order(uv_info.guest_cpu_stor_len));
+	free_page(sida_origin(vcpu->arch.sie_block));
 	vcpu->arch.sie_block->pv_handle_cpu = 0;
 	vcpu->arch.sie_block->pv_handle_config = 0;
 	memset(&vcpu->arch.pv, 0, sizeof(vcpu->arch.pv));
@@ -121,6 +122,14 @@ int kvm_s390_pv_create_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc)
 	uvcb.state_origin = (u64)vcpu->arch.sie_block;
 	uvcb.stor_origin = (u64)vcpu->arch.pv.stor_base;
 
+	/* Alloc Secure Instruction Data Area Designation */
+	vcpu->arch.sie_block->sidad = __get_free_page(GFP_KERNEL | __GFP_ZERO);
+	if (!vcpu->arch.sie_block->sidad) {
+		free_pages(vcpu->arch.pv.stor_base,
+			   get_order(uv_info.guest_cpu_stor_len));
+		return -ENOMEM;
+	}
+
 	cc = uv_call(0, (u64)&uvcb);
 	*rc = uvcb.header.rc;
 	*rrc = uvcb.header.rrc;
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 207915488502..0fdee1bc3798 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -475,11 +475,15 @@ struct kvm_s390_mem_op {
 	__u32 op;		/* type of operation */
 	__u64 buf;		/* buffer in userspace */
 	__u8 ar;		/* the access register number */
-	__u8 reserved[31];	/* should be set to 0 */
+	__u8 reserved21[3];	/* should be set to 0 */
+	__u32 sida_offset;	/* offset into the sida */
+	__u8 reserved28[24];	/* should be set to 0 */
 };
 /* types for kvm_s390_mem_op->op */
 #define KVM_S390_MEMOP_LOGICAL_READ	0
 #define KVM_S390_MEMOP_LOGICAL_WRITE	1
+#define KVM_S390_MEMOP_SIDA_READ	2
+#define KVM_S390_MEMOP_SIDA_WRITE	3
 /* flags for kvm_s390_mem_op->flags */
 #define KVM_S390_MEMOP_F_CHECK_ONLY		(1ULL << 0)
 #define KVM_S390_MEMOP_F_INJECT_EXCEPTION	(1ULL << 1)
-- 
2.25.0


  parent reply index

Thread overview: 81+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-14 22:26 [PATCH v2 00/42] KVM: s390: Add support for protected VMs Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 01/42] mm:gup/writeback: add callbacks for inaccessible pages Christian Borntraeger
2020-02-17  9:14   ` David Hildenbrand
2020-02-17 11:10     ` Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 02/42] KVM: s390/interrupt: do not pin adapter interrupt pages Christian Borntraeger
2020-02-17  9:43   ` David Hildenbrand
2020-02-14 22:26 ` [PATCH v2 03/42] s390/protvirt: introduce host side setup Christian Borntraeger
2020-02-17  9:53   ` David Hildenbrand
2020-02-17 11:11     ` Christian Borntraeger
2020-02-17 11:13       ` David Hildenbrand
2020-02-14 22:26 ` [PATCH v2 04/42] s390/protvirt: add ultravisor initialization Christian Borntraeger
2020-02-17  9:57   ` David Hildenbrand
2020-02-17 11:13     ` Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 05/42] s390/mm: provide memory management functions for protected KVM guests Christian Borntraeger
2020-02-17 10:21   ` David Hildenbrand
2020-02-17 11:28     ` Christian Borntraeger
2020-02-17 12:07       ` David Hildenbrand
2020-02-14 22:26 ` [PATCH v2 06/42] s390/mm: add (non)secure page access exceptions handlers Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 07/42] KVM: s390: protvirt: Add UV debug trace Christian Borntraeger
2020-02-17 10:41   ` David Hildenbrand
2020-02-14 22:26 ` [PATCH v2 08/42] KVM: s390: add new variants of UV CALL Christian Borntraeger
2020-02-17 10:42   ` David Hildenbrand
2020-02-14 22:26 ` [PATCH v2 09/42] KVM: s390: protvirt: Add initial vm and cpu lifecycle handling Christian Borntraeger
2020-02-17 10:56   ` David Hildenbrand
2020-02-17 12:04     ` Christian Borntraeger
2020-02-17 12:09       ` David Hildenbrand
2020-02-17 14:53         ` [PATCH 0/2] example changes Christian Borntraeger
2020-02-17 14:53           ` [PATCH 1/2] lock changes Christian Borntraeger
2020-02-17 14:53           ` [PATCH 2/2] merge vm/cpu create Christian Borntraeger
2020-02-17 15:00             ` Janosch Frank
2020-02-17 15:02               ` Christian Borntraeger
2020-02-17 19:18           ` [PATCH 0/2] example changes David Hildenbrand
2020-02-14 22:26 ` [PATCH v2 10/42] KVM: s390: protvirt: Add KVM api documentation Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 11/42] KVM: s390: protvirt: Secure memory is not mergeable Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 12/42] KVM: s390/mm: Make pages accessible before destroying the guest Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 13/42] KVM: s390: protvirt: Handle SE notification interceptions Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 14/42] KVM: s390: protvirt: Instruction emulation Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 15/42] KVM: s390: protvirt: Add interruption injection controls Christian Borntraeger
2020-02-17 10:59   ` David Hildenbrand
2020-02-14 22:26 ` [PATCH v2 16/42] KVM: s390: protvirt: Implement interruption injection Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 17/42] KVM: s390: protvirt: Add SCLP interrupt handling Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 18/42] KVM: s390: protvirt: Handle spec exception loops Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 19/42] KVM: s390: protvirt: Add new gprs location handling Christian Borntraeger
2020-02-17 11:01   ` David Hildenbrand
2020-02-17 11:33     ` Christian Borntraeger
2020-02-17 14:37     ` Janosch Frank
2020-02-14 22:26 ` Christian Borntraeger [this message]
2020-02-17 11:08   ` [PATCH v2 20/42] KVM: S390: protvirt: Introduce instruction data area bounce buffer David Hildenbrand
2020-02-17 14:47     ` Janosch Frank
2020-02-17 15:00       ` Christian Borntraeger
2020-02-17 15:38         ` Janosch Frank
2020-02-17 16:58           ` Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 21/42] KVM: s390: protvirt: handle secure guest prefix pages Christian Borntraeger
2020-02-17 11:11   ` David Hildenbrand
2020-02-14 22:26 ` [PATCH v2 22/42] KVM: s390/mm: handle guest unpin events Christian Borntraeger
2020-02-17 14:23   ` David Hildenbrand
2020-02-14 22:26 ` [PATCH v2 23/42] KVM: s390: protvirt: Write sthyi data to instruction data area Christian Borntraeger
2020-02-17 14:24   ` David Hildenbrand
2020-02-17 18:40     ` Christian Borntraeger
2020-02-17 19:16       ` David Hildenbrand
2020-02-14 22:26 ` [PATCH v2 24/42] KVM: s390: protvirt: STSI handling Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 25/42] KVM: s390: protvirt: disallow one_reg Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 26/42] KVM: s390: protvirt: Do only reset registers that are accessible Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 27/42] KVM: s390: protvirt: Only sync fmt4 registers Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 28/42] KVM: s390: protvirt: Add program exception injection Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 29/42] KVM: s390: protvirt: Add diag 308 subcode 8 - 10 handling Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 30/42] KVM: s390: protvirt: UV calls in support of diag308 0, 1 Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 31/42] KVM: s390: protvirt: Report CPU state to Ultravisor Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 32/42] KVM: s390: protvirt: Support cmd 5 operation state Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 33/42] KVM: s390: protvirt: Mask PSW interrupt bits for interception 104 and 112 Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 34/42] KVM: s390: protvirt: do not inject interrupts after start Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 35/42] KVM: s390: protvirt: Add UV cpu reset calls Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 36/42] DOCUMENTATION: Protected virtual machine introduction and IPL Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 37/42] s390/uv: Fix handling of length extensions (already in s390 tree) Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 38/42] s390: protvirt: Add sysfs firmware interface for Ultravisor information Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 39/42] example for future extension: mm:gup/writeback: add callbacks for inaccessible pages: error cases Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 40/42] example for future extension: mm:gup/writeback: add callbacks for inaccessible pages: source indication Christian Borntraeger
2020-02-17 14:15   ` Ulrich Weigand
2020-02-17 14:38     ` Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 41/42] potential fixup for "s390/mm: provide memory management functions for protected KVM guests" Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 42/42] KVM: s390: rstify new ioctls in api.rst Christian Borntraeger

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