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Groups > linux.kernel > #1228681
| From | Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 4.1 079/102] KVM: PPC: Book3S HV: Fix race in reading change bit when removing HPTE |
| Date | 2015-09-19 20:30 +0200 |
| Message-ID | <qav3B-W5-47@gated-at.bofh.it> (permalink) |
| References | <qau7v-80f-7@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
4.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Paul Mackerras <paulus@samba.org>
commit 1e5bf454f58731e360e504253e85bae7aaa2d298 upstream.
The reference (R) and change (C) bits in a HPT entry can be set by
hardware at any time up until the HPTE is invalidated and the TLB
invalidation sequence has completed. This means that when removing
a HPTE, we need to read the HPTE after the invalidation sequence has
completed in order to obtain reliable values of R and C. The code
in kvmppc_do_h_remove() used to do this. However, commit 6f22bd3265fb
("KVM: PPC: Book3S HV: Make HTAB code LE host aware") removed the
read after invalidation as a side effect of other changes. This
restores the read of the HPTE after invalidation.
The user-visible effect of this bug would be that when migrating a
guest, there is a small probability that a page modified by the guest
and then unmapped by the guest might not get re-transmitted and thus
the destination might end up with a stale copy of the page.
Fixes: 6f22bd3265fb
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/powerpc/kvm/book3s_hv_rm_mmu.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
@@ -421,14 +421,20 @@ long kvmppc_do_h_remove(struct kvm *kvm,
rev = real_vmalloc_addr(&kvm->arch.revmap[pte_index]);
v = pte & ~HPTE_V_HVLOCK;
if (v & HPTE_V_VALID) {
- u64 pte1;
-
- pte1 = be64_to_cpu(hpte[1]);
hpte[0] &= ~cpu_to_be64(HPTE_V_VALID);
- rb = compute_tlbie_rb(v, pte1, pte_index);
+ rb = compute_tlbie_rb(v, be64_to_cpu(hpte[1]), pte_index);
do_tlbies(kvm, &rb, 1, global_invalidates(kvm, flags), true);
- /* Read PTE low word after tlbie to get final R/C values */
- remove_revmap_chain(kvm, pte_index, rev, v, pte1);
+ /*
+ * The reference (R) and change (C) bits in a HPT
+ * entry can be set by hardware at any time up until
+ * the HPTE is invalidated and the TLB invalidation
+ * sequence has completed. This means that when
+ * removing a HPTE, we need to re-read the HPTE after
+ * the invalidation sequence has completed in order to
+ * obtain reliable values of R and C.
+ */
+ remove_revmap_chain(kvm, pte_index, rev, v,
+ be64_to_cpu(hpte[1]));
}
r = rev->guest_rpte & ~HPTE_GR_RESERVED;
note_hpte_modification(kvm, rev);
--
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[PATCH 4.1 000/102] 4.1.8-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 19:40 +0200
[PATCH 4.1 055/102] xfs: Fix file type directory corruption for btree directories Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 19:40 +0200
[PATCH 4.1 046/102] spi: img-spfi: fix multiple calls to request gpio Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 19:40 +0200
[PATCH 4.1 057/102] doc: usb: gadget-testing: using the updated testusb.c Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:00 +0200
[PATCH 4.1 059/102] usb: gadget: f_uac2: finalize wMaxPacketSize according to bandwidth Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:00 +0200
[PATCH 4.1 058/102] usb: dwc3: ep0: Fix mem corruption on OUT transfers of more than 512 bytes Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:00 +0200
[PATCH 4.1 056/102] usb: gadget: m66592-udc: forever loop in set_feature() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:00 +0200
[PATCH 4.1 100/102] fs: Set the size of empty dirs to 0. Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:20 +0200
[PATCH 4.1 025/102] staging: comedi: adl_pci7x3x: fix digital output on PCI-7230 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:20 +0200
[PATCH 4.1 096/102] ARM: rockchip: fix the CPU soft reset Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:20 +0200
[PATCH 4.1 095/102] ARM: OMAP2+: DRA7: clockdomain: change l4per2_7xx_clkdm to SW_WKUP Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:20 +0200
[PATCH 4.1 101/102] hpfs: update ctime and mtime on directory modification Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:20 +0200
[PATCH 4.1 099/102] drivercore: Fix unregistration path of platform devices Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:20 +0200
[PATCH 4.1 092/102] of/address: Dont loop forever in of_find_matching_node_by_address(). Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:20 +0200
[PATCH 4.1 060/102] usb: host: ehci-sys: delete useless bus_to_hcd conversion Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:20 +0200
[PATCH 4.1 098/102] ACPI, PCI: Penalize legacy IRQ used by ACPI SCI Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:20 +0200
[PATCH 4.1 091/102] soc/tegra: pmc: Avoid usage of uninitialized variable Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:20 +0200
[PATCH 4.1 094/102] ARM: dts: fix clock-frequency of display timing0 for exynos3250-rinato Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:20 +0200
[PATCH 4.1 097/102] ARM: dts: rockchip: fix rk3288 watchdog irq Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:20 +0200
[PATCH 4.1 064/102] ASoC: adav80x: Remove .read_flag_mask setting from adav80x_regmap_config Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:20 +0200
[PATCH 4.1 102/102] fs: create and use seq_show_option for escaping Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:20 +0200
[PATCH 4.1 069/102] serial: 8250_pci: Add support for Pericom PI7C9X795[1248] Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:20 +0200
[PATCH 4.1 089/102] regulator: pbias: Fix broken pbias disable functionality Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:20 +0200
[PATCH 4.1 066/102] ASoC: arizona: Poll for FLL clock OK rather than use interrupts Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:20 +0200
[PATCH 4.1 067/102] serial: 8250: dont bind to SMSC IrCC IR port Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:20 +0200
[PATCH 4.1 063/102] ASoC: samsung: Remove redundant arndale_audio_remove Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:20 +0200
[PATCH 4.1 090/102] x86/mce: Reenable CMCI banks when swiching back to interrupt mode Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:20 +0200
[PATCH 4.1 068/102] serial: 8250: bind to ALi Fast Infrared Controller (ALI5123) Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:20 +0200
[PATCH 4.1 093/102] ARM: orion5x: fix legacy orion5x IRQ numbers Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:20 +0200
[PATCH 4.1 020/102] iio: industrialio-buffer: Fix iio_buffer_poll return value Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 087/102] spi/spi-xilinx: Fix mixed poll/irq mode Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 011/102] drm/i915: Preserve SSC earlier Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 088/102] auxdisplay: ks0108: fix refcount Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 061/102] tty: serial: men_z135_uart.c: Fix race between IRQ and set_termios() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 030/102] clk: exynos4: Fix wrong clock for Exynos4x12 ADC Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 004/102] x86/ldt: Further fix FPU emulation Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 073/102] crypto: ghash-clmulni: specify context size for ghash async algorithm Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 085/102] Doc: ABI: testing: configfs-usb-gadget-sourcesink Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 019/102] iio: event: Remove negative error code from iio_event_poll Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 078/102] KVM: PPC: Book3S HV: Exit on H_DOORBELL if HOST_IPI is set Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 072/102] crypto: vmx - Fixing GHASH Key issue on little endian Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 084/102] Doc: ABI: testing: configfs-usb-gadget-loopback Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 079/102] KVM: PPC: Book3S HV: Fix race in reading change bit when removing HPTE Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 026/102] staging: comedi: usbduxsigma: dont clobber ai_timer in command test Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 010/102] drm/radeon: fix HDMI quantization_range for pre-DCE5 asics Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 082/102] xtensa: fix kernel register spilling Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 077/102] KVM: MMU: fix validation of mmio page fault Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 075/102] HID: cp2112: fix byte order in SMBUS operations Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 029/102] clk: rockchip: rk3288: add CLK_SET_RATE_PARENT to sclk_mac Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 086/102] spi/spi-xilinx: Fix spurious IRQ ACK on irq mode Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 062/102] ASoC: rt5640: fix line out no sound issue Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 081/102] xtensa: fix threadptr reload on return to userspace Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 021/102] iio: adis16400: Fix adis16448 gyroscope scale Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 070/102] serial: samsung: fix DMA mode enter condition for small FIFO sizes Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 071/102] serial: samsung: fix DMA for FIFO smaller than cache line size Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 018/102] iio: bmg160: IIO_BUFFER and IIO_TRIGGERED_BUFFER are required Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 083/102] devres: fix devres_get() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 028/102] PM / clk: dont return int on __pm_clk_enable() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 076/102] HID: cp2112: fix I2C_SMBUS_BYTE write Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 080/102] KVM: x86: Use adjustment in guest cycles when handling MSR_IA32_TSC_ADJUST Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 002/102] x86/ldt: Correct LDT access in single stepping logic Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 003/102] x86/ldt: Correct FPU emulation access to LDT Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:30 +0200
[PATCH 4.1 017/102] s390/setup: fix novx parameter Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:40 +0200
[PATCH 4.1 016/102] s390/sclp: fix compile error Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:40 +0200
[PATCH 4.1 012/102] drm/qxl: validate monitors config modes Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-19 20:40 +0200
Re: [PATCH 4.1 000/102] 4.1.8-stable review Guenter Roeck <linux@roeck-us.net> - 2015-09-19 22:40 +0200
Re: [PATCH 4.1 000/102] 4.1.8-stable review Guenter Roeck <linux@roeck-us.net> - 2015-09-20 02:30 +0200
Re: [PATCH 4.1 000/102] 4.1.8-stable review Willy Tarreau <w@1wt.eu> - 2015-09-20 07:30 +0200
Re: [PATCH 4.1 000/102] 4.1.8-stable review Sudip Mukherjee <sudipm.mukherjee@gmail.com> - 2015-09-20 10:00 +0200
Re: [PATCH 4.1 000/102] 4.1.8-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-21 06:40 +0200
Re: [PATCH 4.1 000/102] 4.1.8-stable review Sudip Mukherjee <sudipm.mukherjee@gmail.com> - 2015-09-21 07:50 +0200
Re: [PATCH 4.1 000/102] 4.1.8-stable review Shuah Khan <shuahkh@osg.samsung.com> - 2015-09-21 18:30 +0200
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