From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Nicolai Stange <nstange@suse.de>,
Thomas Gleixner <tglx@linutronix.de>
Subject: [PATCH 4.14 078/104] x86/KVM/VMX: Initialize the vmx_l1d_flush_pages content
Date: Tue, 14 Aug 2018 19:17:32 +0200 [thread overview]
Message-ID: <20180814171520.316721792@linuxfoundation.org> (raw)
In-Reply-To: <20180814171515.270692185@linuxfoundation.org>
4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Nicolai Stange <nstange@suse.de>
commit 288d152c23dcf3c09da46c5c481903ca10ebfef7 upstream
The slow path in vmx_l1d_flush() reads from vmx_l1d_flush_pages in order
to evict the L1d cache.
However, these pages are never cleared and, in theory, their data could be
leaked.
More importantly, KSM could merge a nested hypervisor's vmx_l1d_flush_pages
to fewer than 1 << L1D_CACHE_ORDER host physical pages and this would break
the L1d flushing algorithm: L1D on x86_64 is tagged by physical addresses.
Fix this by initializing the individual vmx_l1d_flush_pages with a
different pattern each.
Rename the "empty_zp" asm constraint identifier in vmx_l1d_flush() to
"flush_pages" to reflect this change.
Fixes: a47dd5f06714 ("x86/KVM/VMX: Add L1D flush algorithm")
Signed-off-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/kvm/vmx.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -214,6 +214,7 @@ static void *vmx_l1d_flush_pages;
static int vmx_setup_l1d_flush(enum vmx_l1d_flush_state l1tf)
{
struct page *page;
+ unsigned int i;
if (!enable_ept) {
l1tf_vmx_mitigation = VMENTER_L1D_FLUSH_EPT_DISABLED;
@@ -246,6 +247,16 @@ static int vmx_setup_l1d_flush(enum vmx_
if (!page)
return -ENOMEM;
vmx_l1d_flush_pages = page_address(page);
+
+ /*
+ * Initialize each page with a different pattern in
+ * order to protect against KSM in the nested
+ * virtualization case.
+ */
+ for (i = 0; i < 1u << L1D_CACHE_ORDER; ++i) {
+ memset(vmx_l1d_flush_pages + i * PAGE_SIZE, i + 1,
+ PAGE_SIZE);
+ }
}
l1tf_vmx_mitigation = l1tf;
@@ -9176,7 +9187,7 @@ static void vmx_l1d_flush(struct kvm_vcp
/* First ensure the pages are in the TLB */
"xorl %%eax, %%eax\n"
".Lpopulate_tlb:\n\t"
- "movzbl (%[empty_zp], %%" _ASM_AX "), %%ecx\n\t"
+ "movzbl (%[flush_pages], %%" _ASM_AX "), %%ecx\n\t"
"addl $4096, %%eax\n\t"
"cmpl %%eax, %[size]\n\t"
"jne .Lpopulate_tlb\n\t"
@@ -9185,12 +9196,12 @@ static void vmx_l1d_flush(struct kvm_vcp
/* Now fill the cache */
"xorl %%eax, %%eax\n"
".Lfill_cache:\n"
- "movzbl (%[empty_zp], %%" _ASM_AX "), %%ecx\n\t"
+ "movzbl (%[flush_pages], %%" _ASM_AX "), %%ecx\n\t"
"addl $64, %%eax\n\t"
"cmpl %%eax, %[size]\n\t"
"jne .Lfill_cache\n\t"
"lfence\n"
- :: [empty_zp] "r" (vmx_l1d_flush_pages),
+ :: [flush_pages] "r" (vmx_l1d_flush_pages),
[size] "r" (size)
: "eax", "ebx", "ecx", "edx");
}
next prev parent reply other threads:[~2018-08-14 17:38 UTC|newest]
Thread overview: 102+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-14 17:16 [PATCH 4.14 000/104] 4.14.63-stable review Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 001/104] parisc: Enable CONFIG_MLONGCALLS by default Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 003/104] scsi: hpsa: fix selection of reply queue Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 004/104] scsi: core: introduce force_blk_mq Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 005/104] scsi: virtio_scsi: fix IO hang caused by automatic irq vector affinity Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 006/104] kasan: add no_sanitize attribute for clang builds Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 007/104] Mark HI and TASKLET softirq synchronous Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 008/104] stop_machine: Disable preemption after queueing stopper threads Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 009/104] xen/netfront: dont cache skb_shinfo() Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 010/104] scsi: sr: Avoid that opening a CD-ROM hangs with runtime power management enabled Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 011/104] scsi: qla2xxx: Fix memory leak for allocating abort IOCB Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 012/104] init: rename and re-order boot_cpu_state_init() Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 013/104] root dentries need RCU-delayed freeing Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 014/104] make sure that __dentry_kill() always invalidates d_seq, unhashed or not Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 015/104] fix mntput/mntput race Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 016/104] fix __legitimize_mnt()/mntput() race Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 017/104] mtd: nand: qcom: Add a NULL check for devm_kasprintf() Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 018/104] phy: phy-mtk-tphy: use auto instead of force to bypass utmi signals Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 021/104] ARM: dts: imx6sx: fix irq for pcie bridge Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 022/104] x86/paravirt: Fix spectre-v2 mitigations for paravirt guests Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 023/104] x86/speculation: Protect against userspace-userspace spectreRSB Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 024/104] kprobes/x86: Fix %p uses in error messages Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 025/104] x86/irqflags: Provide a declaration for native_save_fl Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 026/104] x86/speculation/l1tf: Increase 32bit PAE __PHYSICAL_PAGE_SHIFT Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 027/104] x86/speculation/l1tf: Change order of offset/type in swap entry Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 028/104] x86/speculation/l1tf: Protect swap entries against L1TF Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 029/104] x86/speculation/l1tf: Protect PROT_NONE PTEs against speculation Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 030/104] x86/speculation/l1tf: Make sure the first page is always reserved Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 031/104] x86/speculation/l1tf: Add sysfs reporting for l1tf Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 032/104] x86/speculation/l1tf: Disallow non privileged high MMIO PROT_NONE mappings Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 033/104] x86/speculation/l1tf: Limit swap file size to MAX_PA/2 Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 034/104] x86/bugs: Move the l1tf function and define pr_fmt properly Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 035/104] sched/smt: Update sched_smt_present at runtime Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 036/104] x86/smp: Provide topology_is_primary_thread() Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 037/104] x86/topology: Provide topology_smt_supported() Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 038/104] cpu/hotplug: Make bringup/teardown of smp threads symmetric Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 039/104] cpu/hotplug: Split do_cpu_down() Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 040/104] cpu/hotplug: Provide knobs to control SMT Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 041/104] x86/cpu: Remove the pointless CPU printout Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 042/104] x86/cpu/AMD: Remove the pointless detect_ht() call Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 043/104] x86/cpu/common: Provide detect_ht_early() Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 044/104] x86/cpu/topology: Provide detect_extended_topology_early() Greg Kroah-Hartman
2018-08-14 17:16 ` [PATCH 4.14 045/104] x86/cpu/intel: Evaluate smp_num_siblings early Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 046/104] x86/CPU/AMD: Do not check CPUID max ext level before parsing SMP info Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 047/104] x86/cpu/AMD: Evaluate smp_num_siblings early Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 049/104] x86/speculation/l1tf: Extend 64bit swap file size limit Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 050/104] x86/cpufeatures: Add detection of L1D cache flush support Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 051/104] x86/CPU/AMD: Move TOPOEXT reenablement before reading smp_num_siblings Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 052/104] x86/speculation/l1tf: Protect PAE swap entries against L1TF Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 053/104] x86/speculation/l1tf: Fix up pte->pfn conversion for PAE Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 054/104] Revert "x86/apic: Ignore secondary threads if nosmt=force" Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 055/104] cpu/hotplug: Boot HT siblings at least once Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 056/104] x86/KVM: Warn user if KVM is loaded SMT and L1TF CPU bug being present Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 057/104] x86/KVM/VMX: Add module argument for L1TF mitigation Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 058/104] x86/KVM/VMX: Add L1D flush algorithm Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 059/104] x86/KVM/VMX: Add L1D MSR based flush Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 060/104] x86/KVM/VMX: Add L1D flush logic Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 061/104] x86/KVM/VMX: Split the VMX MSR LOAD structures to have an host/guest numbers Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 062/104] x86/KVM/VMX: Add find_msr() helper function Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 063/104] x86/KVM/VMX: Separate the VMX AUTOLOAD guest/host number accounting Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 064/104] x86/KVM/VMX: Extend add_atomic_switch_msr() to allow VMENTER only MSRs Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 065/104] x86/KVM/VMX: Use MSR save list for IA32_FLUSH_CMD if required Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 066/104] cpu/hotplug: Online siblings when SMT control is turned on Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 067/104] x86/litf: Introduce vmx status variable Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 068/104] x86/kvm: Drop L1TF MSR list approach Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 069/104] x86/l1tf: Handle EPT disabled state proper Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 070/104] x86/kvm: Move l1tf setup function Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 071/104] x86/kvm: Add static key for flush always Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 072/104] x86/kvm: Serialize L1D flush parameter setter Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 073/104] x86/kvm: Allow runtime control of L1D flush Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 074/104] cpu/hotplug: Expose SMT control init function Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 075/104] cpu/hotplug: Set CPU_SMT_NOT_SUPPORTED early Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 076/104] x86/bugs, kvm: Introduce boot-time control of L1TF mitigations Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 077/104] Documentation: Add section about CPU vulnerabilities Greg Kroah-Hartman
2018-08-14 17:17 ` Greg Kroah-Hartman [this message]
2018-08-14 17:17 ` [PATCH 4.14 079/104] Documentation/l1tf: Fix typos Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 080/104] cpu/hotplug: detect SMT disabled by BIOS Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 081/104] x86/KVM/VMX: Dont set l1tf_flush_l1d to true from vmx_l1d_flush() Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 082/104] x86/KVM/VMX: Replace vmx_l1d_flush_always with vmx_l1d_flush_cond Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 083/104] x86/KVM/VMX: Move the l1tf_flush_l1d test to vmx_l1d_flush() Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 084/104] x86/irq: Demote irq_cpustat_t::__softirq_pending to u16 Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 085/104] x86/KVM/VMX: Introduce per-host-cpu analogue of l1tf_flush_l1d Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 086/104] x86: Dont include linux/irq.h from asm/hardirq.h Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 087/104] x86/irq: Let interrupt handlers set kvm_cpu_l1tf_flush_l1d Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 088/104] x86/KVM/VMX: Dont set l1tf_flush_l1d from vmx_handle_external_intr() Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 089/104] Documentation/l1tf: Remove Yonah processors from not vulnerable list Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 094/104] KVM: VMX: support MSR_IA32_ARCH_CAPABILITIES as a feature MSR Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 095/104] x86/speculation: Simplify sysfs report of VMX L1TF vulnerability Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 096/104] x86/speculation: Use ARCH_CAPABILITIES to skip L1D flush on vmentry Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 097/104] KVM: VMX: Tell the nested hypervisor " Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 098/104] cpu/hotplug: Fix SMT supported evaluation Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 099/104] x86/speculation/l1tf: Invert all not present mappings Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 100/104] x86/speculation/l1tf: Make pmd/pud_mknotpresent() invert Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 101/104] x86/mm/pat: Make set_memory_np() L1TF safe Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 102/104] x86/mm/kmmio: Make the tracer robust against L1TF Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 103/104] tools headers: Synchronise x86 cpufeatures.h for L1TF additions Greg Kroah-Hartman
2018-08-14 17:17 ` [PATCH 4.14 104/104] x86/microcode: Allow late microcode loading with SMT disabled Greg Kroah-Hartman
2018-08-15 6:14 ` [PATCH 4.14 000/104] 4.14.63-stable review Greg Kroah-Hartman
[not found] ` <CA+res+SSVV04eawQ6wDX6_gdd9G0FbQ=uWFy0tOgSX=+T0s2MA@mail.gmail.com>
2018-08-15 15:02 ` Jinpu Wang
2018-08-15 15:31 ` Greg Kroah-Hartman
2018-08-15 13:14 ` Guenter Roeck
2018-08-15 20:38 ` Dan Rue
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