From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Anton Romanov <romanton@google.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Sasha Levin <sashal@kernel.org>,
tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
dave.hansen@linux.intel.com, x86@kernel.org, kvm@vger.kernel.org
Subject: [PATCH AUTOSEL 5.16 06/28] kvm: x86: Disable KVM_HC_CLOCK_PAIRING if tsc is in always catchup mode
Date: Tue, 1 Mar 2022 15:13:11 -0500 [thread overview]
Message-ID: <20220301201344.18191-6-sashal@kernel.org> (raw)
In-Reply-To: <20220301201344.18191-1-sashal@kernel.org>
From: Anton Romanov <romanton@google.com>
[ Upstream commit 3a55f729240a686aa8af00af436306c0cd532522 ]
If vcpu has tsc_always_catchup set each request updates pvclock data.
KVM_HC_CLOCK_PAIRING consumers such as ptp_kvm_x86 rely on tsc read on
host's side and do hypercall inside pvclock_read_retry loop leading to
infinite loop in such situation.
v3:
Removed warn
Changed return code to KVM_EFAULT
v2:
Added warn
Signed-off-by: Anton Romanov <romanton@google.com>
Message-Id: <20220216182653.506850-1-romanton@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/x86/kvm/x86.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0714fa0e7ede0..18fc0367ef21a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8769,6 +8769,13 @@ static int kvm_pv_clock_pairing(struct kvm_vcpu *vcpu, gpa_t paddr,
if (clock_type != KVM_CLOCK_PAIRING_WALLCLOCK)
return -KVM_EOPNOTSUPP;
+ /*
+ * When tsc is in permanent catchup mode guests won't be able to use
+ * pvclock_read_retry loop to get consistent view of pvclock
+ */
+ if (vcpu->arch.tsc_always_catchup)
+ return -KVM_EOPNOTSUPP;
+
if (!kvm_get_walltime_and_clockread(&ts, &cycle))
return -KVM_EOPNOTSUPP;
--
2.34.1
next prev parent reply other threads:[~2022-03-01 20:14 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-01 20:13 [PATCH AUTOSEL 5.16 01/28] selftests/bpf: Add test for bpf_timer overwriting crash Sasha Levin
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 02/28] swiotlb: fix info leak with DMA_FROM_DEVICE Sasha Levin
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 03/28] usb: dwc3: pci: add support for the Intel Raptor Lake-S Sasha Levin
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 04/28] pinctrl: tigerlake: Revert "Add Alder Lake-M ACPI ID" Sasha Levin
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 05/28] KVM: Fix lockdep false negative during host resume Sasha Levin
2022-03-01 20:19 ` Paolo Bonzini
2022-03-01 20:13 ` Sasha Levin [this message]
2022-03-01 20:19 ` [PATCH AUTOSEL 5.16 06/28] kvm: x86: Disable KVM_HC_CLOCK_PAIRING if tsc is in always catchup mode Paolo Bonzini
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 07/28] x86/kvm/fpu: Limit guest user_xfeatures to supported bits of XCR0 Sasha Levin
2022-03-01 20:22 ` Paolo Bonzini
2022-06-03 18:40 ` Peter Xu
2022-06-06 16:18 ` Paolo Bonzini
2022-06-06 21:27 ` Peter Xu
2022-06-07 12:54 ` Paolo Bonzini
2022-06-07 15:04 ` Sean Christopherson
2022-06-07 18:17 ` Peter Xu
2022-06-07 18:47 ` Sean Christopherson
2022-06-07 21:01 ` Peter Xu
2022-06-07 18:55 ` Peter Xu
2022-06-08 20:34 ` Leonardo Bras Soares Passos
2022-06-08 20:53 ` Peter Xu
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 08/28] spi: rockchip: Fix error in getting num-cs property Sasha Levin
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 09/28] spi: rockchip: terminate dma transmission when slave abort Sasha Levin
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 10/28] drm/vc4: hdmi: Unregister codec device on unbind Sasha Levin
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 11/28] of/fdt: move elfcorehdr reservation early for crash dump kernel Sasha Levin
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 12/28] x86/kvm: Don't use pv tlb/ipi/sched_yield if on 1 vCPU Sasha Levin
2022-03-01 20:17 ` Paolo Bonzini
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 13/28] drivers: hamradio: 6pack: fix UAF bug caused by mod_timer() Sasha Levin
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 14/28] net-sysfs: add check for netdevice being present to speed_show Sasha Levin
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 15/28] sr9700: sanity check for packet length Sasha Levin
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 16/28] hwmon: (pmbus) Clear pmbus fault/warning bits after read Sasha Levin
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 17/28] nvme-tcp: send H2CData PDUs based on MAXH2CDATA Sasha Levin
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 18/28] PCI: Mark all AMD Navi10 and Navi14 GPU ATS as broken Sasha Levin
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 19/28] gpio: Return EPROBE_DEFER if gc->to_irq is NULL Sasha Levin
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 20/28] drm/amdgpu: bypass tiling flag check in virtual display case (v2) Sasha Levin
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 21/28] Revert "xen-netback: remove 'hotplug-status' once it has served its purpose" Sasha Levin
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 22/28] Revert "xen-netback: Check for hotplug-status existence before watching" Sasha Levin
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 23/28] ipv6: prevent a possible race condition with lifetimes Sasha Levin
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 24/28] tracing: Ensure trace buffer is at least 4096 bytes large Sasha Levin
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 25/28] tracing/osnoise: Make osnoise_main to sleep for microseconds Sasha Levin
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 26/28] tracing: Fix selftest config check for function graph start up test Sasha Levin
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 27/28] selftest/vm: fix map_fixed_noreplace test failure Sasha Levin
2022-03-01 20:13 ` [PATCH AUTOSEL 5.16 28/28] selftests/memfd: clean up mapping in mfd_fail_write Sasha Levin
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