From: Alexandru Elisei <alexandru.elisei@arm.com>
To: maz@kernel.org, james.morse@arm.com, suzuki.poulose@arm.com,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, will@kernel.org,
linux-kernel@vger.kernel.org
Subject: [RFC PATCH v4 37/39] KVM: arm64: Add PMSIDR_EL1 to the SPE register context
Date: Wed, 25 Aug 2021 17:18:13 +0100 [thread overview]
Message-ID: <20210825161815.266051-38-alexandru.elisei@arm.com> (raw)
In-Reply-To: <20210825161815.266051-1-alexandru.elisei@arm.com>
PMSIDR_EL1 is not part of the VCPU register context because the profiling
control registers were not trapped and the register is read-only. With the
introduction of the KVM_ARM_VCPU_SPE_STOP API, KVM will start trapping
accesses to the profiling control registers, add PMSIDR_EL1 to the VCPU
register context to prevent undefined exceptions in the guest.
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
---
arch/arm64/include/asm/kvm_host.h | 1 +
arch/arm64/kvm/sys_regs.c | 22 +++++++++++++++++++---
2 files changed, 20 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index cc46f1406196..f866c4556ff9 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -247,6 +247,7 @@ enum vcpu_sysreg {
PMSFCR_EL1, /* Sampling Filter Control Register */
PMSEVFR_EL1, /* Sampling Event Filter Register */
PMSLATFR_EL1, /* Sampling Latency Filter Register */
+ PMSIDR_EL1, /* Sampling Profiling ID Register */
PMBLIMITR_EL1, /* Profiling Buffer Limit Address Register */
PMBPTR_EL1, /* Profiling Buffer Write Pointer Register */
PMBSR_EL1, /* Profiling Buffer Status/syndrome Register */
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index cc711b081f31..1a85a0cedbec 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -603,6 +603,18 @@ static unsigned int spe_visibility(const struct kvm_vcpu *vcpu,
return REG_HIDDEN;
}
+static void reset_pmsidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
+{
+ /*
+ * When SPE is stopped by userspace, the guest reads the in-memory value
+ * of the register. When SPE is resumed, accesses to the control
+ * registers are not trapped and the guest reads the hardware
+ * value. Reset PMSIDR_EL1 to the hardware value to avoid mistmatches
+ * between the two.
+ */
+ vcpu_write_sys_reg(vcpu, read_sysreg_s(SYS_PMSIDR_EL1), PMSIDR_EL1);
+}
+
static bool access_spe_reg(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
const struct sys_reg_desc *r)
{ int reg = r->reg;
@@ -613,10 +625,14 @@ static bool access_spe_reg(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
*vcpu_pc(vcpu), *vcpu_cpsr(vcpu));
}
- if (p->is_write)
+ if (p->is_write) {
+ if (reg == PMSIDR_EL1)
+ return write_to_read_only(vcpu, p, r);
+
kvm_spe_write_sysreg(vcpu, reg, val);
- else
+ } else {
p->regval = kvm_spe_read_sysreg(vcpu, reg);
+ }
return true;
}
@@ -1568,7 +1584,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
{ SPE_SYS_REG(SYS_PMSFCR_EL1), .reg = PMSFCR_EL1 },
{ SPE_SYS_REG(SYS_PMSEVFR_EL1), .reg = PMSEVFR_EL1 },
{ SPE_SYS_REG(SYS_PMSLATFR_EL1), .reg = PMSLATFR_EL1 },
- { SPE_SYS_REG(SYS_PMSIDR_EL1), .reset = NULL },
+ { SPE_SYS_REG(SYS_PMSIDR_EL1), .reset = reset_pmsidr, .reg = PMSIDR_EL1 },
{ SPE_SYS_REG(SYS_PMBLIMITR_EL1), .reg = PMBLIMITR_EL1 },
{ SPE_SYS_REG(SYS_PMBPTR_EL1), .reg = PMBPTR_EL1 },
{ SPE_SYS_REG(SYS_PMBSR_EL1), .reg = PMBSR_EL1 },
--
2.33.0
next prev parent reply other threads:[~2021-08-25 16:19 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-25 16:17 [RFC PATCH v4 00/39] KVM: arm64: Add Statistical Profiling Extension (SPE) support Alexandru Elisei
2021-08-25 16:17 ` [RFC PATCH v4 01/39] KVM: arm64: Make lock_all_vcpus() available to the rest of KVM Alexandru Elisei
2021-09-22 10:39 ` Suzuki K Poulose
2021-08-25 16:17 ` [RFC PATCH v4 02/39] KVM: arm64: Add lock/unlock memslot user API Alexandru Elisei
2021-10-18 9:04 ` Suzuki K Poulose
2021-10-18 14:09 ` Alexandru Elisei
2021-08-25 16:17 ` [RFC PATCH v4 03/39] KVM: arm64: Implement the memslot lock/unlock functionality Alexandru Elisei
2021-08-25 16:17 ` [RFC PATCH v4 04/39] KVM: arm64: Defer CMOs for locked memslots until a VCPU is run Alexandru Elisei
2021-10-17 11:43 ` Marc Zyngier
2021-10-18 12:56 ` Alexandru Elisei
2021-08-25 16:17 ` [RFC PATCH v4 05/39] KVM: arm64: Perform CMOs on locked memslots when userspace resets VCPUs Alexandru Elisei
2021-08-25 16:17 ` [RFC PATCH v4 06/39] KVM: arm64: Delay tag scrubbing for locked memslots until a VCPU runs Alexandru Elisei
2021-08-25 16:17 ` [RFC PATCH v4 07/39] KVM: arm64: Unlock memslots after stage 2 tables are freed Alexandru Elisei
2021-08-25 16:17 ` [RFC PATCH v4 08/39] KVM: arm64: Deny changes to locked memslots Alexandru Elisei
2021-08-25 16:17 ` [RFC PATCH v4 09/39] KVM: Add kvm_warn{,_ratelimited} macros Alexandru Elisei
2021-08-25 16:17 ` [RFC PATCH v4 10/39] KVM: arm64: Print a warning for unexpected faults on locked memslots Alexandru Elisei
2021-08-25 16:17 ` [RFC PATCH v4 11/39] KVM: arm64: Allow userspace to lock and unlock memslots Alexandru Elisei
2021-08-25 16:17 ` [RFC PATCH v4 12/39] KVM: arm64: Add the KVM_ARM_VCPU_SUPPORTED_CPUS VCPU ioctl Alexandru Elisei
2021-08-25 16:17 ` [RFC PATCH v4 13/39] KVM: arm64: Add CONFIG_KVM_ARM_SPE Kconfig option Alexandru Elisei
2021-08-25 16:17 ` [RFC PATCH v4 14/39] KVM: arm64: Add SPE capability and VCPU feature Alexandru Elisei
2021-08-25 16:17 ` [RFC PATCH v4 15/39] drivers/perf: Expose the cpumask of CPUs that support SPE Alexandru Elisei
2021-08-25 16:17 ` [RFC PATCH v4 16/39] KVM: arm64: Make SPE available when at least one CPU supports it Alexandru Elisei
2021-08-25 16:17 ` [RFC PATCH v4 17/39] KVM: arm64: Set the VCPU SPE feature bit when SPE is available Alexandru Elisei
2021-08-25 16:17 ` [RFC PATCH v4 18/39] KVM: arm64: Expose SPE version to guests Alexandru Elisei
2021-08-25 16:17 ` [RFC PATCH v4 19/39] KVM: arm64: Do not emulate SPE on CPUs which don't have SPE Alexandru Elisei
2021-08-25 16:17 ` [RFC PATCH v4 20/39] KVM: arm64: Add a new VCPU device control group for SPE Alexandru Elisei
2021-08-25 16:17 ` [RFC PATCH v4 21/39] KVM: arm64: Add SPE VCPU device attribute to set the interrupt number Alexandru Elisei
2021-08-25 16:17 ` [RFC PATCH v4 22/39] KVM: arm64: Add SPE VCPU device attribute to initialize SPE Alexandru Elisei
2021-08-25 16:17 ` [RFC PATCH v4 23/39] KVM: arm64: VHE: Clear MDCR_EL2.E2PB in vcpu_put() Alexandru Elisei
2021-08-25 16:18 ` [RFC PATCH v4 24/39] KVM: arm64: debug: Configure MDCR_EL2 when a VCPU has SPE Alexandru Elisei
2021-08-25 16:18 ` [RFC PATCH v4 25/39] KVM: arm64: Move the write to MDCR_EL2 out of __activate_traps_common() Alexandru Elisei
2021-08-25 16:18 ` [RFC PATCH v4 26/39] KVM: arm64: VHE: Change MDCR_EL2 at world switch if VCPU has SPE Alexandru Elisei
2021-08-25 16:18 ` [RFC PATCH v4 27/39] KVM: arm64: Add SPE system registers to VCPU context Alexandru Elisei
2021-08-25 16:18 ` [RFC PATCH v4 28/39] KVM: arm64: nVHE: Save PMSCR_EL1 to the host context Alexandru Elisei
2021-08-25 16:18 ` [RFC PATCH v4 29/39] KVM: arm64: Rename DEBUG_STATE_SAVE_SPE -> DEBUG_SAVE_SPE_BUFFER flags Alexandru Elisei
2021-08-25 16:18 ` [RFC PATCH v4 30/39] KVM: arm64: nVHE: Context switch SPE state if VCPU has SPE Alexandru Elisei
2021-08-25 16:18 ` [RFC PATCH v4 31/39] KVM: arm64: VHE: " Alexandru Elisei
2021-08-25 16:18 ` [RFC PATCH v4 32/39] KVM: arm64: Save/restore PMSNEVFR_EL1 on VCPU put/load Alexandru Elisei
2021-08-25 16:18 ` [RFC PATCH v4 33/39] KVM: arm64: Allow guest to use physical timestamps if perfmon_capable() Alexandru Elisei
2021-08-25 16:18 ` [RFC PATCH v4 34/39] KVM: arm64: Emulate SPE buffer management interrupt Alexandru Elisei
2021-08-25 16:18 ` [RFC PATCH v4 35/39] KVM: arm64: Add an userspace API to stop a VCPU profiling Alexandru Elisei
2021-08-25 16:18 ` [RFC PATCH v4 36/39] KVM: arm64: Implement " Alexandru Elisei
2021-08-25 16:18 ` Alexandru Elisei [this message]
2021-08-25 16:18 ` [RFC PATCH v4 38/39] KVM: arm64: Make CONFIG_KVM_ARM_SPE depend on !CONFIG_NUMA_BALANCING Alexandru Elisei
2021-08-25 16:18 ` [RFC PATCH v4 39/39] KVM: arm64: Allow userspace to enable SPE for guests Alexandru Elisei
2021-09-22 10:11 ` [RFC PATCH v4 00/39] KVM: arm64: Add Statistical Profiling Extension (SPE) support Suzuki K Poulose
2021-09-23 15:12 ` Alexandru Elisei
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