August 2020 - Linux-stable-mirror

patch "xhci: Do warm-reset when both CAS and XDEV_RESUME are set" added to usb-linus

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled xhci: Do warm-reset when both CAS and XDEV_RESUME are set to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-linus branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will hopefully also be merged in Linus's tree for the next -rc kernel release. If you have any questions about this process, please let me know. >From 904df64a5f4d5ebd670801d869ca0a6d6a6e8df6 Mon Sep 17 00:00:00 2001 From: Kai-Heng Feng <kai.heng.feng(a)canonical.com> Date: Fri, 21 Aug 2020 12:15:48 +0300 Subject: xhci: Do warm-reset when both CAS and XDEV_RESUME are set Sometimes re-plugging a USB device during system sleep renders the device useless: [ 173.418345] xhci_hcd 0000:00:14.0: Get port status 2-4 read: 0x14203e2, return 0x10262 ... [ 176.496485] usb 2-4: Waited 2000ms for CONNECT [ 176.496781] usb usb2-port4: status 0000.0262 after resume, -19 [ 176.497103] usb 2-4: can't resume, status -19 [ 176.497438] usb usb2-port4: logical disconnect Because PLS equals to XDEV_RESUME, xHCI driver reports U3 to usbcore, despite of CAS bit is flagged. So proritize CAS over XDEV_RESUME to let usbcore handle warm-reset for the port. Cc: stable <stable(a)vger.kernel.org> Signed-off-by: Kai-Heng Feng <kai.heng.feng(a)canonical.com> Signed-off-by: Mathias Nyman <mathias.nyman(a)linux.intel.com> Link: https://lore.kernel.org/r/20200821091549.20556-3-mathias.nyman@linux.intel.… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/usb/host/xhci-hub.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c index c3554e37e09f..4e14e164cb68 100644 --- a/drivers/usb/host/xhci-hub.c +++ b/drivers/usb/host/xhci-hub.c @@ -740,15 +740,6 @@ static void xhci_hub_report_usb3_link_state(struct xhci_hcd *xhci, { u32 pls = status_reg & PORT_PLS_MASK; - /* resume state is a xHCI internal state. - * Do not report it to usb core, instead, pretend to be U3, - * thus usb core knows it's not ready for transfer - */ - if (pls == XDEV_RESUME) { - *status |= USB_SS_PORT_LS_U3; - return; - } - /* When the CAS bit is set then warm reset * should be performed on port */ @@ -770,6 +761,16 @@ static void xhci_hub_report_usb3_link_state(struct xhci_hcd *xhci, */ pls |= USB_PORT_STAT_CONNECTION; } else { + /* + * Resume state is an xHCI internal state. Do not report it to + * usb core, instead, pretend to be U3, thus usb core knows + * it's not ready for transfer. + */ + if (pls == XDEV_RESUME) { + *status |= USB_SS_PORT_LS_U3; + return; + } + /* * If CAS bit isn't set but the Port is already at * Compliance Mode, fake a connection so the USB core -- 2.28.0

4 years, 4 months

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patch "usb: host: xhci: fix ep context print mismatch in debugfs" added to usb-linus

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled usb: host: xhci: fix ep context print mismatch in debugfs to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-linus branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will hopefully also be merged in Linus's tree for the next -rc kernel release. If you have any questions about this process, please let me know. >From 0077b1b2c8d9ad5f7a08b62fb8524cdb9938388f Mon Sep 17 00:00:00 2001 From: Li Jun <jun.li(a)nxp.com> Date: Fri, 21 Aug 2020 12:15:47 +0300 Subject: usb: host: xhci: fix ep context print mismatch in debugfs dci is 0 based and xhci_get_ep_ctx() will do ep index increment to get the ep context. [rename dci to ep_index -Mathias] Cc: stable <stable(a)vger.kernel.org> # v4.15+ Fixes: 02b6fdc2a153 ("usb: xhci: Add debugfs interface for xHCI driver") Signed-off-by: Li Jun <jun.li(a)nxp.com> Signed-off-by: Mathias Nyman <mathias.nyman(a)linux.intel.com> Link: https://lore.kernel.org/r/20200821091549.20556-2-mathias.nyman@linux.intel.… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/usb/host/xhci-debugfs.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/usb/host/xhci-debugfs.c b/drivers/usb/host/xhci-debugfs.c index 92e25a62fdb5..c88bffd68742 100644 --- a/drivers/usb/host/xhci-debugfs.c +++ b/drivers/usb/host/xhci-debugfs.c @@ -274,7 +274,7 @@ static int xhci_slot_context_show(struct seq_file *s, void *unused) static int xhci_endpoint_context_show(struct seq_file *s, void *unused) { - int dci; + int ep_index; dma_addr_t dma; struct xhci_hcd *xhci; struct xhci_ep_ctx *ep_ctx; @@ -283,9 +283,9 @@ static int xhci_endpoint_context_show(struct seq_file *s, void *unused) xhci = hcd_to_xhci(bus_to_hcd(dev->udev->bus)); - for (dci = 1; dci < 32; dci++) { - ep_ctx = xhci_get_ep_ctx(xhci, dev->out_ctx, dci); - dma = dev->out_ctx->dma + dci * CTX_SIZE(xhci->hcc_params); + for (ep_index = 0; ep_index < 31; ep_index++) { + ep_ctx = xhci_get_ep_ctx(xhci, dev->out_ctx, ep_index); + dma = dev->out_ctx->dma + (ep_index + 1) * CTX_SIZE(xhci->hcc_params); seq_printf(s, "%pad: %s\n", &dma, xhci_decode_ep_context(le32_to_cpu(ep_ctx->ep_info), le32_to_cpu(ep_ctx->ep_info2), -- 2.28.0

4 years, 4 months

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FAILED: patch "[PATCH] opp: Enable resources again if they were disabled earlier" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From a4501bac0e553bed117b7e1b166d49731caf7260 Mon Sep 17 00:00:00 2001 From: Rajendra Nayak <rnayak(a)codeaurora.org> Date: Mon, 10 Aug 2020 12:36:19 +0530 Subject: [PATCH] opp: Enable resources again if they were disabled earlier dev_pm_opp_set_rate() can now be called with freq = 0 in order to either drop performance or bandwidth votes or to disable regulators on platforms which support them. In such cases, a subsequent call to dev_pm_opp_set_rate() with the same frequency ends up returning early because 'old_freq == freq' Instead make it fall through and put back the dropped performance and bandwidth votes and/or enable back the regulators. Cc: v5.3+ <stable(a)vger.kernel.org> # v5.3+ Fixes: cd7ea582866f ("opp: Make dev_pm_opp_set_rate() handle freq = 0 to drop performance votes") Reported-by: Sajida Bhanu <sbhanu(a)codeaurora.org> Reviewed-by: Sibi Sankar <sibis(a)codeaurora.org> Reported-by: Matthias Kaehlcke <mka(a)chromium.org> Tested-by: Matthias Kaehlcke <mka(a)chromium.org> Reviewed-by: Stephen Boyd <sboyd(a)kernel.org> Signed-off-by: Rajendra Nayak <rnayak(a)codeaurora.org> [ Viresh: Don't skip clk_set_rate() and massaged changelog ] Signed-off-by: Viresh Kumar <viresh.kumar(a)linaro.org> diff --git a/drivers/opp/core.c b/drivers/opp/core.c index bdb028c7793d..9668ea04cc80 100644 --- a/drivers/opp/core.c +++ b/drivers/opp/core.c @@ -934,10 +934,13 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq) /* Return early if nothing to do */ if (old_freq == freq) { - dev_dbg(dev, "%s: old/new frequencies (%lu Hz) are same, nothing to do\n", - __func__, freq); - ret = 0; - goto put_opp_table; + if (!opp_table->required_opp_tables && !opp_table->regulators && + !opp_table->paths) { + dev_dbg(dev, "%s: old/new frequencies (%lu Hz) are same, nothing to do\n", + __func__, freq); + ret = 0; + goto put_opp_table; + } } /*

4 years, 4 months

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FAILED: patch "[PATCH] opp: Enable resources again if they were disabled earlier" failed to apply to 5.7-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.7-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From a4501bac0e553bed117b7e1b166d49731caf7260 Mon Sep 17 00:00:00 2001 From: Rajendra Nayak <rnayak(a)codeaurora.org> Date: Mon, 10 Aug 2020 12:36:19 +0530 Subject: [PATCH] opp: Enable resources again if they were disabled earlier dev_pm_opp_set_rate() can now be called with freq = 0 in order to either drop performance or bandwidth votes or to disable regulators on platforms which support them. In such cases, a subsequent call to dev_pm_opp_set_rate() with the same frequency ends up returning early because 'old_freq == freq' Instead make it fall through and put back the dropped performance and bandwidth votes and/or enable back the regulators. Cc: v5.3+ <stable(a)vger.kernel.org> # v5.3+ Fixes: cd7ea582866f ("opp: Make dev_pm_opp_set_rate() handle freq = 0 to drop performance votes") Reported-by: Sajida Bhanu <sbhanu(a)codeaurora.org> Reviewed-by: Sibi Sankar <sibis(a)codeaurora.org> Reported-by: Matthias Kaehlcke <mka(a)chromium.org> Tested-by: Matthias Kaehlcke <mka(a)chromium.org> Reviewed-by: Stephen Boyd <sboyd(a)kernel.org> Signed-off-by: Rajendra Nayak <rnayak(a)codeaurora.org> [ Viresh: Don't skip clk_set_rate() and massaged changelog ] Signed-off-by: Viresh Kumar <viresh.kumar(a)linaro.org> diff --git a/drivers/opp/core.c b/drivers/opp/core.c index bdb028c7793d..9668ea04cc80 100644 --- a/drivers/opp/core.c +++ b/drivers/opp/core.c @@ -934,10 +934,13 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq) /* Return early if nothing to do */ if (old_freq == freq) { - dev_dbg(dev, "%s: old/new frequencies (%lu Hz) are same, nothing to do\n", - __func__, freq); - ret = 0; - goto put_opp_table; + if (!opp_table->required_opp_tables && !opp_table->regulators && + !opp_table->paths) { + dev_dbg(dev, "%s: old/new frequencies (%lu Hz) are same, nothing to do\n", + __func__, freq); + ret = 0; + goto put_opp_table; + } } /*

4 years, 4 months

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FAILED: patch "[PATCH] drm/i915: Provide the perf pmu.module" failed to apply to 5.8-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.8-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From df3ab3cb7eae63c6eb7c9aebcc196a75d59f65dd Mon Sep 17 00:00:00 2001 From: Chris Wilson <chris(a)chris-wilson.co.uk> Date: Thu, 16 Jul 2020 10:46:43 +0100 Subject: [PATCH] drm/i915: Provide the perf pmu.module Rather than manually implement our own module reference counting for perf pmu events, finally realise that there is a module parameter to struct pmu for this very purpose. Signed-off-by: Chris Wilson <chris(a)chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin(a)intel.com> Cc: stable(a)vger.kernel.org Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin(a)intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200716094643.31410-1-chris@… Signed-off-by: Rodrigo Vivi <rodrigo.vivi(a)intel.com> (cherry picked from commit 27e897beec1c59861f15d4d3562c39ad1143620f) Signed-off-by: Jani Nikula <jani.nikula(a)intel.com> diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c index 28bc5f13ae52..056994224c6b 100644 --- a/drivers/gpu/drm/i915/i915_pmu.c +++ b/drivers/gpu/drm/i915/i915_pmu.c @@ -445,8 +445,6 @@ static void i915_pmu_event_destroy(struct perf_event *event) container_of(event->pmu, typeof(*i915), pmu.base); drm_WARN_ON(&i915->drm, event->parent); - - module_put(THIS_MODULE); } static int @@ -538,10 +536,8 @@ static int i915_pmu_event_init(struct perf_event *event) if (ret) return ret; - if (!event->parent) { - __module_get(THIS_MODULE); + if (!event->parent) event->destroy = i915_pmu_event_destroy; - } return 0; } @@ -1130,6 +1126,7 @@ void i915_pmu_register(struct drm_i915_private *i915) if (!pmu->base.attr_groups) goto err_attr; + pmu->base.module = THIS_MODULE; pmu->base.task_ctx_nr = perf_invalid_context; pmu->base.event_init = i915_pmu_event_init; pmu->base.add = i915_pmu_event_add;

4 years, 4 months

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FAILED: patch "[PATCH] KVM: arm64: Only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE" failed to apply to 4.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From b5331379bc62611d1026173a09c73573384201d9 Mon Sep 17 00:00:00 2001 From: Will Deacon <will(a)kernel.org> Date: Tue, 11 Aug 2020 11:27:25 +0100 Subject: [PATCH] KVM: arm64: Only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE is not set When an MMU notifier call results in unmapping a range that spans multiple PGDs, we end up calling into cond_resched_lock() when crossing a PGD boundary, since this avoids running into RCU stalls during VM teardown. Unfortunately, if the VM is destroyed as a result of OOM, then blocking is not permitted and the call to the scheduler triggers the following BUG(): | BUG: sleeping function called from invalid context at arch/arm64/kvm/mmu.c:394 | in_atomic(): 1, irqs_disabled(): 0, non_block: 1, pid: 36, name: oom_reaper | INFO: lockdep is turned off. | CPU: 3 PID: 36 Comm: oom_reaper Not tainted 5.8.0 #1 | Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 | Call trace: | dump_backtrace+0x0/0x284 | show_stack+0x1c/0x28 | dump_stack+0xf0/0x1a4 | ___might_sleep+0x2bc/0x2cc | unmap_stage2_range+0x160/0x1ac | kvm_unmap_hva_range+0x1a0/0x1c8 | kvm_mmu_notifier_invalidate_range_start+0x8c/0xf8 | __mmu_notifier_invalidate_range_start+0x218/0x31c | mmu_notifier_invalidate_range_start_nonblock+0x78/0xb0 | __oom_reap_task_mm+0x128/0x268 | oom_reap_task+0xac/0x298 | oom_reaper+0x178/0x17c | kthread+0x1e4/0x1fc | ret_from_fork+0x10/0x30 Use the new 'flags' argument to kvm_unmap_hva_range() to ensure that we only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE is set in the notifier flags. Cc: <stable(a)vger.kernel.org> Fixes: 8b3405e345b5 ("kvm: arm/arm64: Fix locking for kvm_free_stage2_pgd") Cc: Marc Zyngier <maz(a)kernel.org> Cc: Suzuki K Poulose <suzuki.poulose(a)arm.com> Cc: James Morse <james.morse(a)arm.com> Signed-off-by: Will Deacon <will(a)kernel.org> Message-Id: <20200811102725.7121-3-will(a)kernel.org> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index dc351802ff18..ba00bcc0c884 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -343,7 +343,8 @@ static void unmap_stage2_p4ds(struct kvm_s2_mmu *mmu, pgd_t *pgd, * destroying the VM), otherwise another faulting VCPU may come in and mess * with things behind our backs. */ -static void unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size) +static void __unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size, + bool may_block) { struct kvm *kvm = mmu->kvm; pgd_t *pgd; @@ -369,11 +370,16 @@ static void unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 si * If the range is too large, release the kvm->mmu_lock * to prevent starvation and lockup detector warnings. */ - if (next != end) + if (may_block && next != end) cond_resched_lock(&kvm->mmu_lock); } while (pgd++, addr = next, addr != end); } +static void unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size) +{ + __unmap_stage2_range(mmu, start, size, true); +} + static void stage2_flush_ptes(struct kvm_s2_mmu *mmu, pmd_t *pmd, phys_addr_t addr, phys_addr_t end) { @@ -2208,7 +2214,10 @@ static int handle_hva_to_gpa(struct kvm *kvm, static int kvm_unmap_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data) { - unmap_stage2_range(&kvm->arch.mmu, gpa, size); + unsigned flags = *(unsigned *)data; + bool may_block = flags & MMU_NOTIFIER_RANGE_BLOCKABLE; + + __unmap_stage2_range(&kvm->arch.mmu, gpa, size, may_block); return 0; } @@ -2219,7 +2228,7 @@ int kvm_unmap_hva_range(struct kvm *kvm, return 0; trace_kvm_unmap_hva_range(start, end); - handle_hva_to_gpa(kvm, start, end, &kvm_unmap_hva_handler, NULL); + handle_hva_to_gpa(kvm, start, end, &kvm_unmap_hva_handler, &flags); return 0; }

4 years, 4 months

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FAILED: patch "[PATCH] KVM: arm64: Only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE" failed to apply to 4.14-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From b5331379bc62611d1026173a09c73573384201d9 Mon Sep 17 00:00:00 2001 From: Will Deacon <will(a)kernel.org> Date: Tue, 11 Aug 2020 11:27:25 +0100 Subject: [PATCH] KVM: arm64: Only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE is not set When an MMU notifier call results in unmapping a range that spans multiple PGDs, we end up calling into cond_resched_lock() when crossing a PGD boundary, since this avoids running into RCU stalls during VM teardown. Unfortunately, if the VM is destroyed as a result of OOM, then blocking is not permitted and the call to the scheduler triggers the following BUG(): | BUG: sleeping function called from invalid context at arch/arm64/kvm/mmu.c:394 | in_atomic(): 1, irqs_disabled(): 0, non_block: 1, pid: 36, name: oom_reaper | INFO: lockdep is turned off. | CPU: 3 PID: 36 Comm: oom_reaper Not tainted 5.8.0 #1 | Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 | Call trace: | dump_backtrace+0x0/0x284 | show_stack+0x1c/0x28 | dump_stack+0xf0/0x1a4 | ___might_sleep+0x2bc/0x2cc | unmap_stage2_range+0x160/0x1ac | kvm_unmap_hva_range+0x1a0/0x1c8 | kvm_mmu_notifier_invalidate_range_start+0x8c/0xf8 | __mmu_notifier_invalidate_range_start+0x218/0x31c | mmu_notifier_invalidate_range_start_nonblock+0x78/0xb0 | __oom_reap_task_mm+0x128/0x268 | oom_reap_task+0xac/0x298 | oom_reaper+0x178/0x17c | kthread+0x1e4/0x1fc | ret_from_fork+0x10/0x30 Use the new 'flags' argument to kvm_unmap_hva_range() to ensure that we only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE is set in the notifier flags. Cc: <stable(a)vger.kernel.org> Fixes: 8b3405e345b5 ("kvm: arm/arm64: Fix locking for kvm_free_stage2_pgd") Cc: Marc Zyngier <maz(a)kernel.org> Cc: Suzuki K Poulose <suzuki.poulose(a)arm.com> Cc: James Morse <james.morse(a)arm.com> Signed-off-by: Will Deacon <will(a)kernel.org> Message-Id: <20200811102725.7121-3-will(a)kernel.org> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index dc351802ff18..ba00bcc0c884 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -343,7 +343,8 @@ static void unmap_stage2_p4ds(struct kvm_s2_mmu *mmu, pgd_t *pgd, * destroying the VM), otherwise another faulting VCPU may come in and mess * with things behind our backs. */ -static void unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size) +static void __unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size, + bool may_block) { struct kvm *kvm = mmu->kvm; pgd_t *pgd; @@ -369,11 +370,16 @@ static void unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 si * If the range is too large, release the kvm->mmu_lock * to prevent starvation and lockup detector warnings. */ - if (next != end) + if (may_block && next != end) cond_resched_lock(&kvm->mmu_lock); } while (pgd++, addr = next, addr != end); } +static void unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size) +{ + __unmap_stage2_range(mmu, start, size, true); +} + static void stage2_flush_ptes(struct kvm_s2_mmu *mmu, pmd_t *pmd, phys_addr_t addr, phys_addr_t end) { @@ -2208,7 +2214,10 @@ static int handle_hva_to_gpa(struct kvm *kvm, static int kvm_unmap_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data) { - unmap_stage2_range(&kvm->arch.mmu, gpa, size); + unsigned flags = *(unsigned *)data; + bool may_block = flags & MMU_NOTIFIER_RANGE_BLOCKABLE; + + __unmap_stage2_range(&kvm->arch.mmu, gpa, size, may_block); return 0; } @@ -2219,7 +2228,7 @@ int kvm_unmap_hva_range(struct kvm *kvm, return 0; trace_kvm_unmap_hva_range(start, end); - handle_hva_to_gpa(kvm, start, end, &kvm_unmap_hva_handler, NULL); + handle_hva_to_gpa(kvm, start, end, &kvm_unmap_hva_handler, &flags); return 0; }

4 years, 4 months

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FAILED: patch "[PATCH] KVM: arm64: Only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From b5331379bc62611d1026173a09c73573384201d9 Mon Sep 17 00:00:00 2001 From: Will Deacon <will(a)kernel.org> Date: Tue, 11 Aug 2020 11:27:25 +0100 Subject: [PATCH] KVM: arm64: Only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE is not set When an MMU notifier call results in unmapping a range that spans multiple PGDs, we end up calling into cond_resched_lock() when crossing a PGD boundary, since this avoids running into RCU stalls during VM teardown. Unfortunately, if the VM is destroyed as a result of OOM, then blocking is not permitted and the call to the scheduler triggers the following BUG(): | BUG: sleeping function called from invalid context at arch/arm64/kvm/mmu.c:394 | in_atomic(): 1, irqs_disabled(): 0, non_block: 1, pid: 36, name: oom_reaper | INFO: lockdep is turned off. | CPU: 3 PID: 36 Comm: oom_reaper Not tainted 5.8.0 #1 | Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 | Call trace: | dump_backtrace+0x0/0x284 | show_stack+0x1c/0x28 | dump_stack+0xf0/0x1a4 | ___might_sleep+0x2bc/0x2cc | unmap_stage2_range+0x160/0x1ac | kvm_unmap_hva_range+0x1a0/0x1c8 | kvm_mmu_notifier_invalidate_range_start+0x8c/0xf8 | __mmu_notifier_invalidate_range_start+0x218/0x31c | mmu_notifier_invalidate_range_start_nonblock+0x78/0xb0 | __oom_reap_task_mm+0x128/0x268 | oom_reap_task+0xac/0x298 | oom_reaper+0x178/0x17c | kthread+0x1e4/0x1fc | ret_from_fork+0x10/0x30 Use the new 'flags' argument to kvm_unmap_hva_range() to ensure that we only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE is set in the notifier flags. Cc: <stable(a)vger.kernel.org> Fixes: 8b3405e345b5 ("kvm: arm/arm64: Fix locking for kvm_free_stage2_pgd") Cc: Marc Zyngier <maz(a)kernel.org> Cc: Suzuki K Poulose <suzuki.poulose(a)arm.com> Cc: James Morse <james.morse(a)arm.com> Signed-off-by: Will Deacon <will(a)kernel.org> Message-Id: <20200811102725.7121-3-will(a)kernel.org> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index dc351802ff18..ba00bcc0c884 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -343,7 +343,8 @@ static void unmap_stage2_p4ds(struct kvm_s2_mmu *mmu, pgd_t *pgd, * destroying the VM), otherwise another faulting VCPU may come in and mess * with things behind our backs. */ -static void unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size) +static void __unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size, + bool may_block) { struct kvm *kvm = mmu->kvm; pgd_t *pgd; @@ -369,11 +370,16 @@ static void unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 si * If the range is too large, release the kvm->mmu_lock * to prevent starvation and lockup detector warnings. */ - if (next != end) + if (may_block && next != end) cond_resched_lock(&kvm->mmu_lock); } while (pgd++, addr = next, addr != end); } +static void unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size) +{ + __unmap_stage2_range(mmu, start, size, true); +} + static void stage2_flush_ptes(struct kvm_s2_mmu *mmu, pmd_t *pmd, phys_addr_t addr, phys_addr_t end) { @@ -2208,7 +2214,10 @@ static int handle_hva_to_gpa(struct kvm *kvm, static int kvm_unmap_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data) { - unmap_stage2_range(&kvm->arch.mmu, gpa, size); + unsigned flags = *(unsigned *)data; + bool may_block = flags & MMU_NOTIFIER_RANGE_BLOCKABLE; + + __unmap_stage2_range(&kvm->arch.mmu, gpa, size, may_block); return 0; } @@ -2219,7 +2228,7 @@ int kvm_unmap_hva_range(struct kvm *kvm, return 0; trace_kvm_unmap_hva_range(start, end); - handle_hva_to_gpa(kvm, start, end, &kvm_unmap_hva_handler, NULL); + handle_hva_to_gpa(kvm, start, end, &kvm_unmap_hva_handler, &flags); return 0; }

4 years, 4 months

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FAILED: patch "[PATCH] KVM: arm64: Only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From b5331379bc62611d1026173a09c73573384201d9 Mon Sep 17 00:00:00 2001 From: Will Deacon <will(a)kernel.org> Date: Tue, 11 Aug 2020 11:27:25 +0100 Subject: [PATCH] KVM: arm64: Only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE is not set When an MMU notifier call results in unmapping a range that spans multiple PGDs, we end up calling into cond_resched_lock() when crossing a PGD boundary, since this avoids running into RCU stalls during VM teardown. Unfortunately, if the VM is destroyed as a result of OOM, then blocking is not permitted and the call to the scheduler triggers the following BUG(): | BUG: sleeping function called from invalid context at arch/arm64/kvm/mmu.c:394 | in_atomic(): 1, irqs_disabled(): 0, non_block: 1, pid: 36, name: oom_reaper | INFO: lockdep is turned off. | CPU: 3 PID: 36 Comm: oom_reaper Not tainted 5.8.0 #1 | Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 | Call trace: | dump_backtrace+0x0/0x284 | show_stack+0x1c/0x28 | dump_stack+0xf0/0x1a4 | ___might_sleep+0x2bc/0x2cc | unmap_stage2_range+0x160/0x1ac | kvm_unmap_hva_range+0x1a0/0x1c8 | kvm_mmu_notifier_invalidate_range_start+0x8c/0xf8 | __mmu_notifier_invalidate_range_start+0x218/0x31c | mmu_notifier_invalidate_range_start_nonblock+0x78/0xb0 | __oom_reap_task_mm+0x128/0x268 | oom_reap_task+0xac/0x298 | oom_reaper+0x178/0x17c | kthread+0x1e4/0x1fc | ret_from_fork+0x10/0x30 Use the new 'flags' argument to kvm_unmap_hva_range() to ensure that we only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE is set in the notifier flags. Cc: <stable(a)vger.kernel.org> Fixes: 8b3405e345b5 ("kvm: arm/arm64: Fix locking for kvm_free_stage2_pgd") Cc: Marc Zyngier <maz(a)kernel.org> Cc: Suzuki K Poulose <suzuki.poulose(a)arm.com> Cc: James Morse <james.morse(a)arm.com> Signed-off-by: Will Deacon <will(a)kernel.org> Message-Id: <20200811102725.7121-3-will(a)kernel.org> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index dc351802ff18..ba00bcc0c884 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -343,7 +343,8 @@ static void unmap_stage2_p4ds(struct kvm_s2_mmu *mmu, pgd_t *pgd, * destroying the VM), otherwise another faulting VCPU may come in and mess * with things behind our backs. */ -static void unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size) +static void __unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size, + bool may_block) { struct kvm *kvm = mmu->kvm; pgd_t *pgd; @@ -369,11 +370,16 @@ static void unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 si * If the range is too large, release the kvm->mmu_lock * to prevent starvation and lockup detector warnings. */ - if (next != end) + if (may_block && next != end) cond_resched_lock(&kvm->mmu_lock); } while (pgd++, addr = next, addr != end); } +static void unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size) +{ + __unmap_stage2_range(mmu, start, size, true); +} + static void stage2_flush_ptes(struct kvm_s2_mmu *mmu, pmd_t *pmd, phys_addr_t addr, phys_addr_t end) { @@ -2208,7 +2214,10 @@ static int handle_hva_to_gpa(struct kvm *kvm, static int kvm_unmap_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data) { - unmap_stage2_range(&kvm->arch.mmu, gpa, size); + unsigned flags = *(unsigned *)data; + bool may_block = flags & MMU_NOTIFIER_RANGE_BLOCKABLE; + + __unmap_stage2_range(&kvm->arch.mmu, gpa, size, may_block); return 0; } @@ -2219,7 +2228,7 @@ int kvm_unmap_hva_range(struct kvm *kvm, return 0; trace_kvm_unmap_hva_range(start, end); - handle_hva_to_gpa(kvm, start, end, &kvm_unmap_hva_handler, NULL); + handle_hva_to_gpa(kvm, start, end, &kvm_unmap_hva_handler, &flags); return 0; }

4 years, 4 months

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FAILED: patch "[PATCH] KVM: arm64: Only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From b5331379bc62611d1026173a09c73573384201d9 Mon Sep 17 00:00:00 2001 From: Will Deacon <will(a)kernel.org> Date: Tue, 11 Aug 2020 11:27:25 +0100 Subject: [PATCH] KVM: arm64: Only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE is not set When an MMU notifier call results in unmapping a range that spans multiple PGDs, we end up calling into cond_resched_lock() when crossing a PGD boundary, since this avoids running into RCU stalls during VM teardown. Unfortunately, if the VM is destroyed as a result of OOM, then blocking is not permitted and the call to the scheduler triggers the following BUG(): | BUG: sleeping function called from invalid context at arch/arm64/kvm/mmu.c:394 | in_atomic(): 1, irqs_disabled(): 0, non_block: 1, pid: 36, name: oom_reaper | INFO: lockdep is turned off. | CPU: 3 PID: 36 Comm: oom_reaper Not tainted 5.8.0 #1 | Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 | Call trace: | dump_backtrace+0x0/0x284 | show_stack+0x1c/0x28 | dump_stack+0xf0/0x1a4 | ___might_sleep+0x2bc/0x2cc | unmap_stage2_range+0x160/0x1ac | kvm_unmap_hva_range+0x1a0/0x1c8 | kvm_mmu_notifier_invalidate_range_start+0x8c/0xf8 | __mmu_notifier_invalidate_range_start+0x218/0x31c | mmu_notifier_invalidate_range_start_nonblock+0x78/0xb0 | __oom_reap_task_mm+0x128/0x268 | oom_reap_task+0xac/0x298 | oom_reaper+0x178/0x17c | kthread+0x1e4/0x1fc | ret_from_fork+0x10/0x30 Use the new 'flags' argument to kvm_unmap_hva_range() to ensure that we only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE is set in the notifier flags. Cc: <stable(a)vger.kernel.org> Fixes: 8b3405e345b5 ("kvm: arm/arm64: Fix locking for kvm_free_stage2_pgd") Cc: Marc Zyngier <maz(a)kernel.org> Cc: Suzuki K Poulose <suzuki.poulose(a)arm.com> Cc: James Morse <james.morse(a)arm.com> Signed-off-by: Will Deacon <will(a)kernel.org> Message-Id: <20200811102725.7121-3-will(a)kernel.org> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index dc351802ff18..ba00bcc0c884 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -343,7 +343,8 @@ static void unmap_stage2_p4ds(struct kvm_s2_mmu *mmu, pgd_t *pgd, * destroying the VM), otherwise another faulting VCPU may come in and mess * with things behind our backs. */ -static void unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size) +static void __unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size, + bool may_block) { struct kvm *kvm = mmu->kvm; pgd_t *pgd; @@ -369,11 +370,16 @@ static void unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 si * If the range is too large, release the kvm->mmu_lock * to prevent starvation and lockup detector warnings. */ - if (next != end) + if (may_block && next != end) cond_resched_lock(&kvm->mmu_lock); } while (pgd++, addr = next, addr != end); } +static void unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size) +{ + __unmap_stage2_range(mmu, start, size, true); +} + static void stage2_flush_ptes(struct kvm_s2_mmu *mmu, pmd_t *pmd, phys_addr_t addr, phys_addr_t end) { @@ -2208,7 +2214,10 @@ static int handle_hva_to_gpa(struct kvm *kvm, static int kvm_unmap_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data) { - unmap_stage2_range(&kvm->arch.mmu, gpa, size); + unsigned flags = *(unsigned *)data; + bool may_block = flags & MMU_NOTIFIER_RANGE_BLOCKABLE; + + __unmap_stage2_range(&kvm->arch.mmu, gpa, size, may_block); return 0; } @@ -2219,7 +2228,7 @@ int kvm_unmap_hva_range(struct kvm *kvm, return 0; trace_kvm_unmap_hva_range(start, end); - handle_hva_to_gpa(kvm, start, end, &kvm_unmap_hva_handler, NULL); + handle_hva_to_gpa(kvm, start, end, &kvm_unmap_hva_handler, &flags); return 0; }

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Linux-stable-mirror August 2020