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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	James Morse <james.morse@arm.com>,
	Marc Zyngier <marc.zyngier@arm.com>,
	Andre Przywara <andre.przywara@arm.com>
Subject: [PATCH 4.9 53/71] KVM: arm64: Defer guest entry when an asynchronous exception is pending
Date: Fri, 11 Sep 2020 14:46:37 +0200	[thread overview]
Message-ID: <20200911122507.555558810@linuxfoundation.org> (raw)
In-Reply-To: <20200911122504.928931589@linuxfoundation.org>

From: James Morse <james.morse@arm.com>

commit 5dcd0fdbb492d49dac6bf21c436dfcb5ded0a895 upstream.

SError that occur during world-switch's entry to the guest will be
accounted to the guest, as the exception is masked until we enter the
guest... but we want to attribute the SError as precisely as possible.

Reading DISR_EL1 before guest entry requires free registers, and using
ESB+DISR_EL1 to consume and read back the ESR would leave KVM holding
a host SError... We would rather leave the SError pending and let the
host take it once we exit world-switch. To do this, we need to defer
guest-entry if an SError is pending.

Read the ISR to see if SError (or an IRQ) is pending. If so fake an
exit. Place this check between __guest_enter()'s save of the host
registers, and restore of the guest's. SError that occur between
here and the eret into the guest must have affected the guest's
registers, which we can naturally attribute to the guest.

The dsb is needed to ensure any previous writes have been done before
we read ISR_EL1. On systems without the v8.2 RAS extensions this
doesn't give us anything as we can't contain errors, and the ESR bits
to describe the severity are all implementation-defined. Replace
this with a nop for these systems.

v4.9-backport: as this kernel version doesn't have the RAS support at
all, remove the RAS alternative.

Cc: stable@vger.kernel.org # v4.9
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
[ James: Removed v8.2 RAS related barriers ]
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/arm64/kvm/hyp/entry.S |   10 ++++++++++
 1 file changed, 10 insertions(+)

--- a/arch/arm64/kvm/hyp/entry.S
+++ b/arch/arm64/kvm/hyp/entry.S
@@ -17,6 +17,7 @@
 
 #include <linux/linkage.h>
 
+#include <asm/alternative.h>
 #include <asm/asm-offsets.h>
 #include <asm/assembler.h>
 #include <asm/fpsimdmacros.h>
@@ -62,6 +63,15 @@ ENTRY(__guest_enter)
 	// Store the host regs
 	save_callee_saved_regs x1
 
+	// Now the host state is stored if we have a pending RAS SError it must
+	// affect the host. If any asynchronous exception is pending we defer
+	// the guest entry.
+	mrs	x1, isr_el1
+	cbz	x1,  1f
+	mov	x0, #ARM_EXCEPTION_IRQ
+	ret
+
+1:
 	add	x18, x0, #VCPU_CONTEXT
 
 	// Restore guest regs x0-x17



  parent reply	other threads:[~2020-09-11 13:43 UTC|newest]

Thread overview: 75+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-11 12:45 [PATCH 4.9 00/71] 4.9.236-rc1 review Greg Kroah-Hartman
2020-09-11 12:45 ` [PATCH 4.9 01/71] HID: core: Correctly handle ReportSize being zero Greg Kroah-Hartman
2020-09-11 12:45 ` [PATCH 4.9 02/71] HID: core: Sanitize event code and type when mapping input Greg Kroah-Hartman
2020-09-11 12:45 ` [PATCH 4.9 03/71] perf record/stat: Explicitly call out event modifiers in the documentation Greg Kroah-Hartman
2020-09-11 12:45 ` [PATCH 4.9 04/71] hwmon: (applesmc) check status earlier Greg Kroah-Hartman
2020-09-11 12:45 ` [PATCH 4.9 05/71] nvmet: Disable keep-alive timer when kato is cleared to 0h Greg Kroah-Hartman
2020-09-11 12:45 ` [PATCH 4.9 06/71] ceph: dont allow setlease on cephfs Greg Kroah-Hartman
2020-09-11 12:45 ` [PATCH 4.9 07/71] s390: dont trace preemption in percpu macros Greg Kroah-Hartman
2020-09-11 12:45 ` [PATCH 4.9 08/71] xen/xenbus: Fix granting of vmallocd memory Greg Kroah-Hartman
2020-09-11 12:45 ` [PATCH 4.9 09/71] dmaengine: of-dma: Fix of_dma_router_xlates of_dma_xlate handling Greg Kroah-Hartman
2020-09-11 12:45 ` [PATCH 4.9 10/71] batman-adv: Avoid uninitialized chaddr when handling DHCP Greg Kroah-Hartman
2020-09-11 12:45 ` [PATCH 4.9 11/71] batman-adv: bla: use netif_rx_ni when not in interrupt context Greg Kroah-Hartman
2020-09-11 12:45 ` [PATCH 4.9 12/71] dmaengine: at_hdmac: check return value of of_find_device_by_node() in at_dma_xlate() Greg Kroah-Hartman
2020-09-11 12:45 ` [PATCH 4.9 13/71] MIPS: mm: BMIPS5000 has inclusive physical caches Greg Kroah-Hartman
2020-09-11 12:45 ` [PATCH 4.9 14/71] MIPS: BMIPS: Also call bmips_cpu_setup() for secondary cores Greg Kroah-Hartman
2020-09-11 12:45 ` [PATCH 4.9 15/71] netfilter: nf_tables: add NFTA_SET_USERDATA if not null Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 16/71] netfilter: nf_tables: incorrect enum nft_list_attributes definition Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 17/71] netfilter: nf_tables: fix destination register zeroing Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 18/71] net: hns: Fix memleak in hns_nic_dev_probe Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 19/71] ravb: Fixed to be able to unload modules Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 20/71] net: arc_emac: Fix memleak in arc_mdio_probe Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 21/71] dmaengine: pl330: Fix burst length if burst size is smaller than bus width Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 22/71] bnxt_en: Check for zero dir entries in NVRAM Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 23/71] bnxt_en: Fix PCI AER error recovery flow Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 24/71] fix regression in "epoll: Keep a reference on files added to the check list" Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 25/71] tg3: Fix soft lockup when tg3_reset_task() fails Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 26/71] iommu/vt-d: Serialize IOMMU GCMD register modifications Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 27/71] thermal: ti-soc-thermal: Fix bogus thermal shutdowns for omap4430 Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 28/71] include/linux/log2.h: add missing () around n in roundup_pow_of_two() Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 29/71] btrfs: drop path before adding new uuid tree entry Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 30/71] btrfs: Remove redundant extent_buffer_get in get_old_root Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 31/71] btrfs: Remove extraneous extent_buffer_get from tree_mod_log_rewind Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 32/71] btrfs: set the lockdep class for log tree extent buffers Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 33/71] uaccess: Add non-pagefault user-space read functions Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 34/71] uaccess: Add non-pagefault user-space write function Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 35/71] btrfs: fix potential deadlock in the search ioctl Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 36/71] net: usb: qmi_wwan: add Telit 0x1050 composition Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 37/71] drivers: net: usb: qmi_wwan: add QMI_QUIRK_SET_DTR for Telit PID 0x1201 Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 38/71] qmi_wwan: new Telewell and Sierra device IDs Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 39/71] usb: qmi_wwan: add D-Link DWM-222 A2 device ID Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 40/71] ALSA: ca0106: fix error code handling Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 41/71] ALSA: pcm: oss: Remove superfluous WARN_ON() for mulaw sanity check Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 42/71] ALSA: firewire-digi00x: exclude Avid Adrenaline from detection Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 43/71] block: allow for_each_bvec to support zero len bvec Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 44/71] block: Move SECTOR_SIZE and SECTOR_SHIFT definitions into <linux/blkdev.h> Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 45/71] libata: implement ATA_HORKAGE_MAX_TRIM_128M and apply to Sandisks Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 46/71] dm cache metadata: Avoid returning cmd->bm wild pointer on error Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 47/71] dm thin " Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 48/71] mm: slub: fix conversion of freelist_corrupted() Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 49/71] vfio/type1: Support faulting PFNMAP vmas Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 50/71] vfio-pci: Fault mmaps to enable vma tracking Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 51/71] vfio-pci: Invalidate mmaps and block MMIO access on disabled memory Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 52/71] KVM: arm64: Add kvm_extable for vaxorcism code Greg Kroah-Hartman
2020-09-11 12:46 ` Greg Kroah-Hartman [this message]
2020-09-11 12:46 ` [PATCH 4.9 54/71] KVM: arm64: Survive synchronous exceptions caused by AT instructions Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 55/71] KVM: arm64: Set HCR_EL2.PTW to prevent AT taking synchronous exception Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 56/71] net: refactor bind_bucket fastreuse into helper Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 57/71] net: initialize fastreuse on inet_inherit_port Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 58/71] vfio/pci: Fix SR-IOV VF handling with MMIO blocking Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 59/71] checkpatch: fix the usage of capture group ( ... ) Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 60/71] mm/hugetlb: fix a race between hugetlb sysctl handlers Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 61/71] cfg80211: regulatory: reject invalid hints Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 62/71] net: usb: Fix uninit-was-stored issue in asix_read_phy_addr() Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 63/71] ALSA; firewire-tascam: exclude Tascam FE-8 from detection Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 64/71] fs/affs: use octal for permissions Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 65/71] affs: fix basic permission bits to actually work Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 66/71] net: ethernet: mlx4: Fix memory allocation in mlx4_buddy_init() Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 67/71] bnxt: dont enable NAPI until rings are ready Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 68/71] netlabel: fix problems with mapping removal Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 69/71] net: usb: dm9601: Add USB ID of Keenetic Plus DSL Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 70/71] sctp: not disable bh in the whole sctp_get_port_local() Greg Kroah-Hartman
2020-09-11 12:46 ` [PATCH 4.9 71/71] net: disable netpoll on fresh napis Greg Kroah-Hartman
2020-09-11 22:31 ` [PATCH 4.9 00/71] 4.9.236-rc1 review Shuah Khan
2020-09-12  2:16 ` Guenter Roeck
2020-09-12  8:06 ` Naresh Kamboju

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