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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 27/42] KVM: s390: protvirt: Only sync fmt4 registers
Date: Fri, 14 Feb 2020 17:26:43 -0500
Message-ID: <20200214222658.12946-28-borntraeger@de.ibm.com> (raw)
In-Reply-To: <20200214222658.12946-1-borntraeger@de.ibm.com>

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

A lot of the registers are controlled by the Ultravisor and never
visible to KVM. Also some registers are overlayed, like gbea is with
sidad, which might leak data to userspace.

Hence we sync a minimal set of registers for both SIE formats and then
check and sync format 2 registers if necessary.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
[borntraeger@de.ibm.com: patch merging, splitting, fixing]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
 arch/s390/kvm/kvm-s390.c | 110 +++++++++++++++++++++++++--------------
 1 file changed, 70 insertions(+), 40 deletions(-)

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 5b551cc73540..4a97d3b7840e 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -4048,7 +4048,7 @@ static int __vcpu_run(struct kvm_vcpu *vcpu)
 	return rc;
 }
 
-static void sync_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
+static void sync_regs_fmt2(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 {
 	struct runtime_instr_cb *riccb;
 	struct gs_cb *gscb;
@@ -4057,16 +4057,7 @@ static void sync_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 	gscb = (struct gs_cb *) &kvm_run->s.regs.gscb;
 	vcpu->arch.sie_block->gpsw.mask = kvm_run->psw_mask;
 	vcpu->arch.sie_block->gpsw.addr = kvm_run->psw_addr;
-	if (kvm_run->kvm_dirty_regs & KVM_SYNC_PREFIX)
-		kvm_s390_set_prefix(vcpu, kvm_run->s.regs.prefix);
-	if (kvm_run->kvm_dirty_regs & KVM_SYNC_CRS) {
-		memcpy(&vcpu->arch.sie_block->gcr, &kvm_run->s.regs.crs, 128);
-		/* some control register changes require a tlb flush */
-		kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
-	}
 	if (kvm_run->kvm_dirty_regs & KVM_SYNC_ARCH0) {
-		kvm_s390_set_cpu_timer(vcpu, kvm_run->s.regs.cputm);
-		vcpu->arch.sie_block->ckc = kvm_run->s.regs.ckc;
 		vcpu->arch.sie_block->todpr = kvm_run->s.regs.todpr;
 		vcpu->arch.sie_block->pp = kvm_run->s.regs.pp;
 		vcpu->arch.sie_block->gbea = kvm_run->s.regs.gbea;
@@ -4107,6 +4098,36 @@ static void sync_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 		vcpu->arch.sie_block->fpf &= ~FPF_BPBC;
 		vcpu->arch.sie_block->fpf |= kvm_run->s.regs.bpbc ? FPF_BPBC : 0;
 	}
+	if (MACHINE_HAS_GS) {
+		preempt_disable();
+		__ctl_set_bit(2, 4);
+		if (current->thread.gs_cb) {
+			vcpu->arch.host_gscb = current->thread.gs_cb;
+			save_gs_cb(vcpu->arch.host_gscb);
+		}
+		if (vcpu->arch.gs_enabled) {
+			current->thread.gs_cb = (struct gs_cb *)
+						&vcpu->run->s.regs.gscb;
+			restore_gs_cb(current->thread.gs_cb);
+		}
+		preempt_enable();
+	}
+	/* SIE will load etoken directly from SDNX and therefore kvm_run */
+}
+
+static void sync_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
+{
+	if (kvm_run->kvm_dirty_regs & KVM_SYNC_PREFIX)
+		kvm_s390_set_prefix(vcpu, kvm_run->s.regs.prefix);
+	if (kvm_run->kvm_dirty_regs & KVM_SYNC_CRS) {
+		memcpy(&vcpu->arch.sie_block->gcr, &kvm_run->s.regs.crs, 128);
+		/* some control register changes require a tlb flush */
+		kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
+	}
+	if (kvm_run->kvm_dirty_regs & KVM_SYNC_ARCH0) {
+		kvm_s390_set_cpu_timer(vcpu, kvm_run->s.regs.cputm);
+		vcpu->arch.sie_block->ckc = kvm_run->s.regs.ckc;
+	}
 	save_access_regs(vcpu->arch.host_acrs);
 	restore_access_regs(vcpu->run->s.regs.acrs);
 	/* save host (userspace) fprs/vrs */
@@ -4121,23 +4142,47 @@ static void sync_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 	if (test_fp_ctl(current->thread.fpu.fpc))
 		/* User space provided an invalid FPC, let's clear it */
 		current->thread.fpu.fpc = 0;
+
+	/* Sync fmt2 only data */
+	if (likely(!kvm_s390_pv_is_protected(vcpu->kvm))) {
+		sync_regs_fmt2(vcpu, kvm_run);
+	} else {
+		/*
+		 * In several places we have to modify our internal view to
+		 * not do things that are disallowed by the ultravisor. For
+		 * example we must not inject interrupts after specific exits
+		 * (e.g. 112 prefix page not secure). We do this by turning
+		 * off the machine check, external and I/O interrupt bits
+		 * of our PSW copy. To avoid getting validity intercepts, we
+		 * do only accept the condition code from userspace.
+		 */
+		vcpu->arch.sie_block->gpsw.mask &= ~PSW_MASK_CC;
+		vcpu->arch.sie_block->gpsw.mask |= kvm_run->psw_mask &
+						   PSW_MASK_CC;
+	}
+
+	kvm_run->kvm_dirty_regs = 0;
+}
+
+static void store_regs_fmt2(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
+{
+	kvm_run->s.regs.todpr = vcpu->arch.sie_block->todpr;
+	kvm_run->s.regs.pp = vcpu->arch.sie_block->pp;
+	kvm_run->s.regs.gbea = vcpu->arch.sie_block->gbea;
+	kvm_run->s.regs.bpbc = (vcpu->arch.sie_block->fpf & FPF_BPBC) == FPF_BPBC;
 	if (MACHINE_HAS_GS) {
-		preempt_disable();
 		__ctl_set_bit(2, 4);
-		if (current->thread.gs_cb) {
-			vcpu->arch.host_gscb = current->thread.gs_cb;
-			save_gs_cb(vcpu->arch.host_gscb);
-		}
-		if (vcpu->arch.gs_enabled) {
-			current->thread.gs_cb = (struct gs_cb *)
-						&vcpu->run->s.regs.gscb;
-			restore_gs_cb(current->thread.gs_cb);
-		}
+		if (vcpu->arch.gs_enabled)
+			save_gs_cb(current->thread.gs_cb);
+		preempt_disable();
+		current->thread.gs_cb = vcpu->arch.host_gscb;
+		restore_gs_cb(vcpu->arch.host_gscb);
 		preempt_enable();
+		if (!vcpu->arch.host_gscb)
+			__ctl_clear_bit(2, 4);
+		vcpu->arch.host_gscb = NULL;
 	}
-	/* SIE will load etoken directly from SDNX and therefore kvm_run */
-
-	kvm_run->kvm_dirty_regs = 0;
+	/* SIE will save etoken directly into SDNX and therefore kvm_run */
 }
 
 static void store_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
@@ -4148,13 +4193,9 @@ static void store_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 	memcpy(&kvm_run->s.regs.crs, &vcpu->arch.sie_block->gcr, 128);
 	kvm_run->s.regs.cputm = kvm_s390_get_cpu_timer(vcpu);
 	kvm_run->s.regs.ckc = vcpu->arch.sie_block->ckc;
-	kvm_run->s.regs.todpr = vcpu->arch.sie_block->todpr;
-	kvm_run->s.regs.pp = vcpu->arch.sie_block->pp;
-	kvm_run->s.regs.gbea = vcpu->arch.sie_block->gbea;
 	kvm_run->s.regs.pft = vcpu->arch.pfault_token;
 	kvm_run->s.regs.pfs = vcpu->arch.pfault_select;
 	kvm_run->s.regs.pfc = vcpu->arch.pfault_compare;
-	kvm_run->s.regs.bpbc = (vcpu->arch.sie_block->fpf & FPF_BPBC) == FPF_BPBC;
 	save_access_regs(vcpu->run->s.regs.acrs);
 	restore_access_regs(vcpu->arch.host_acrs);
 	/* Save guest register state */
@@ -4163,19 +4204,8 @@ static void store_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 	/* Restore will be done lazily at return */
 	current->thread.fpu.fpc = vcpu->arch.host_fpregs.fpc;
 	current->thread.fpu.regs = vcpu->arch.host_fpregs.regs;
-	if (MACHINE_HAS_GS) {
-		__ctl_set_bit(2, 4);
-		if (vcpu->arch.gs_enabled)
-			save_gs_cb(current->thread.gs_cb);
-		preempt_disable();
-		current->thread.gs_cb = vcpu->arch.host_gscb;
-		restore_gs_cb(vcpu->arch.host_gscb);
-		preempt_enable();
-		if (!vcpu->arch.host_gscb)
-			__ctl_clear_bit(2, 4);
-		vcpu->arch.host_gscb = NULL;
-	}
-	/* SIE will save etoken directly into SDNX and therefore kvm_run */
+	if (likely(!kvm_s390_pv_is_protected(vcpu->kvm)))
+		store_regs_fmt2(vcpu, kvm_run);
 }
 
 int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
-- 
2.25.0


  parent reply index

Thread overview: 132+ 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
2020-02-18  8:27       ` David Hildenbrand
2020-02-18 15:46         ` Sean Christopherson
2020-02-18 16:02           ` Will Deacon
2020-02-18 16:15             ` Christian Borntraeger
2020-02-18 21:35               ` Sean Christopherson
2020-02-19  8:31                 ` David Hildenbrand
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
2020-02-20 12:18     ` David Hildenbrand
2020-02-20 13:31     ` Christian Borntraeger
2020-02-20 13:34       ` 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
2020-02-19 11:02               ` Christian Borntraeger
2020-02-17 19:18           ` [PATCH 0/2] example changes David Hildenbrand
2020-02-18  8:09     ` [PATCH v2 09/42] KVM: s390: protvirt: Add initial vm and cpu lifecycle handling Christian Borntraeger
2020-02-18  8:39   ` [PATCH v2.1] " Christian Borntraeger
2020-02-18  9:12     ` David Hildenbrand
2020-02-18 21:18       ` Christian Borntraeger
2020-02-19  8:32         ` David Hildenbrand
2020-02-19 11:01       ` Christian Borntraeger
2020-02-18  9:56     ` David Hildenbrand
2020-02-18 20:26       ` Christian Borntraeger
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 ` [PATCH v2 20/42] KVM: S390: protvirt: Introduce instruction data area bounce buffer Christian Borntraeger
2020-02-17 11:08   ` 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
2020-02-18  8:35   ` David Hildenbrand
2020-02-18  8:44     ` Christian Borntraeger
2020-02-18  9:08       ` David Hildenbrand
2020-02-18  9:11         ` Christian Borntraeger
2020-02-18  9:13           ` David Hildenbrand
2020-02-14 22:26 ` [PATCH v2 25/42] KVM: s390: protvirt: disallow one_reg Christian Borntraeger
2020-02-18  8:40   ` David Hildenbrand
2020-02-18  8:57     ` Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 26/42] KVM: s390: protvirt: Do only reset registers that are accessible Christian Borntraeger
2020-02-18  8:42   ` David Hildenbrand
2020-02-18  9:20     ` Christian Borntraeger
2020-02-18  9:28       ` David Hildenbrand
2020-02-14 22:26 ` Christian Borntraeger [this message]
2020-02-14 22:26 ` [PATCH v2 28/42] KVM: s390: protvirt: Add program exception injection Christian Borntraeger
2020-02-18  9:33   ` David Hildenbrand
2020-02-18  9:37     ` Christian Borntraeger
2020-02-18  9:39       ` David Hildenbrand
2020-02-14 22:26 ` [PATCH v2 29/42] KVM: s390: protvirt: Add diag 308 subcode 8 - 10 handling Christian Borntraeger
2020-02-18  9:38   ` David Hildenbrand
2020-02-19 12:45     ` Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 30/42] KVM: s390: protvirt: UV calls in support of diag308 0, 1 Christian Borntraeger
2020-02-18  9:44   ` David Hildenbrand
2020-02-19 11:53     ` Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 31/42] KVM: s390: protvirt: Report CPU state to Ultravisor Christian Borntraeger
2020-02-18  9:48   ` David Hildenbrand
2020-02-19 19:36     ` Christian Borntraeger
2020-02-19 19:46       ` Christian Borntraeger
2020-02-20 10:52         ` David Hildenbrand
2020-02-14 22:26 ` [PATCH v2 32/42] KVM: s390: protvirt: Support cmd 5 operation state Christian Borntraeger
2020-02-18  9:50   ` David Hildenbrand
2020-02-19 11:06     ` Christian Borntraeger
2020-02-19 11:08       ` David Hildenbrand
2020-02-14 22:26 ` [PATCH v2 33/42] KVM: s390: protvirt: Mask PSW interrupt bits for interception 104 and 112 Christian Borntraeger
2020-02-18  9:53   ` David Hildenbrand
2020-02-18 10:02     ` David Hildenbrand
2020-02-18 10:05     ` Christian Borntraeger
2020-02-14 22:26 ` [PATCH v2 34/42] KVM: s390: protvirt: do not inject interrupts after start Christian Borntraeger
2020-02-18  9:53   ` David Hildenbrand
2020-02-18 10:02     ` David Hildenbrand
2020-02-14 22:26 ` [PATCH v2 35/42] KVM: s390: protvirt: Add UV cpu reset calls Christian Borntraeger
2020-02-18  9:54   ` David Hildenbrand
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
2020-02-18 16:25   ` Will Deacon
2020-02-18 16:30     ` Christian Borntraeger
2020-02-18 16:33       ` Will Deacon
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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