From: Oliver Upton <oupton@google.com>
To: kvmarm@lists.cs.columbia.edu
Cc: kvm@vger.kernel.org, Marc Zyngier <maz@kernel.org>,
James Morse <james.morse@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
linux-arm-kernel@lists.infradead.org,
Andrew Jones <drjones@redhat.com>,
Peter Shier <pshier@google.com>,
Ricardo Koller <ricarkol@google.com>,
Reiji Watanabe <reijiw@google.com>,
Oliver Upton <oupton@google.com>
Subject: [PATCH v2 2/6] KVM: arm64: Stash OSLSR_EL1 in the cpu context
Date: Tue, 2 Nov 2021 09:46:47 +0000 [thread overview]
Message-ID: <20211102094651.2071532-3-oupton@google.com> (raw)
In-Reply-To: <20211102094651.2071532-1-oupton@google.com>
An upcoming change to KVM will context switch the OS Lock status between
guest/host. Add OSLSR_EL1 to the cpu context and handle guest reads
using the stored value.
Wire up a custom handler for writes from userspace and prevent any of
the invariant bits from changing.
Signed-off-by: Oliver Upton <oupton@google.com>
---
arch/arm64/include/asm/kvm_host.h | 1 +
arch/arm64/kvm/sys_regs.c | 31 ++++++++++++++++++++++++-------
2 files changed, 25 insertions(+), 7 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index f8be56d5342b..c98f65c4a1f7 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -172,6 +172,7 @@ enum vcpu_sysreg {
MDSCR_EL1, /* Monitor Debug System Control Register */
MDCCINT_EL1, /* Monitor Debug Comms Channel Interrupt Enable Reg */
DISR_EL1, /* Deferred Interrupt Status Register */
+ OSLSR_EL1, /* OS Lock Status Register */
/* Performance Monitors Registers */
PMCR_EL0, /* Control Register */
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 17fa6ddf5405..0326b3df0736 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -291,12 +291,28 @@ static bool trap_oslsr_el1(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
- if (p->is_write) {
+ if (p->is_write)
return write_to_read_only(vcpu, p, r);
- } else {
- p->regval = (1 << 3);
- return true;
- }
+
+ p->regval = __vcpu_sys_reg(vcpu, r->reg);
+ return true;
+}
+
+static int set_oslsr_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
+ const struct kvm_one_reg *reg, void __user *uaddr)
+{
+ u64 id = sys_reg_to_index(rd);
+ u64 val;
+ int err;
+
+ err = reg_from_user(&val, uaddr, id);
+ if (err)
+ return err;
+
+ if (val != rd->val)
+ return -EINVAL;
+
+ return 0;
}
static bool trap_dbgauthstatus_el1(struct kvm_vcpu *vcpu,
@@ -1441,7 +1457,8 @@ static const struct sys_reg_desc sys_reg_descs[] = {
{ SYS_DESC(SYS_MDRAR_EL1), trap_raz_wi },
{ SYS_DESC(SYS_OSLAR_EL1), trap_raz_wi },
- { SYS_DESC(SYS_OSLSR_EL1), trap_oslsr_el1 },
+ { SYS_DESC(SYS_OSLSR_EL1), trap_oslsr_el1, reset_val, OSLSR_EL1, 0x00000008,
+ .set_user = set_oslsr_el1, },
{ SYS_DESC(SYS_OSDLR_EL1), trap_raz_wi },
{ SYS_DESC(SYS_DBGPRCR_EL1), trap_raz_wi },
{ SYS_DESC(SYS_DBGCLAIMSET_EL1), trap_raz_wi },
@@ -1916,7 +1933,7 @@ static const struct sys_reg_desc cp14_regs[] = {
{ Op1( 0), CRn( 1), CRm( 0), Op2( 4), trap_raz_wi },
DBGBXVR(1),
/* DBGOSLSR */
- { Op1( 0), CRn( 1), CRm( 1), Op2( 4), trap_oslsr_el1 },
+ { Op1( 0), CRn( 1), CRm( 1), Op2( 4), trap_oslsr_el1, NULL, OSLSR_EL1 },
DBGBXVR(2),
DBGBXVR(3),
/* DBGOSDLR */
--
2.33.1.1089.g2158813163f-goog
next prev parent reply other threads:[~2021-11-02 9:47 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-02 9:46 [PATCH v2 0/6] KVM: arm64: Emulate the OS lock Oliver Upton
2021-11-02 9:46 ` [PATCH v2 1/6] KVM: arm64: Correctly treat writes to OSLSR_EL1 as undefined Oliver Upton
2021-11-04 2:40 ` Reiji Watanabe
2021-11-02 9:46 ` Oliver Upton [this message]
2021-11-02 9:51 ` [PATCH v2 2/6] KVM: arm64: Stash OSLSR_EL1 in the cpu context Oliver Upton
2021-11-04 3:37 ` Reiji Watanabe
2021-11-02 9:46 ` [PATCH v2 3/6] KVM: arm64: Allow guest to set the OSLK bit Oliver Upton
2021-11-04 3:31 ` Reiji Watanabe
2021-11-04 3:47 ` Ricardo Koller
2021-11-04 4:40 ` Oliver Upton
2021-11-02 9:46 ` [PATCH v2 4/6] KVM: arm64: Emulate the OS Lock Oliver Upton
2021-11-02 23:45 ` Ricardo Koller
2021-11-03 0:35 ` Oliver Upton
2021-11-05 3:56 ` Reiji Watanabe
2021-11-05 5:36 ` Oliver Upton
2021-11-02 9:46 ` [PATCH v2 5/6] selftests: KVM: Add OSLSR_EL1 to the list of blessed regs Oliver Upton
2021-11-02 9:46 ` [PATCH v2 6/6] selftests: KVM: Test OS lock behavior Oliver Upton
2021-11-02 11:09 ` Marc Zyngier
2021-11-02 14:53 ` Oliver Upton
2021-11-02 20:01 ` Oliver Upton
2021-11-02 23:27 ` Ricardo Koller
2021-11-02 23:36 ` Oliver Upton
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