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authorVitaly Kuznetsov <vkuznets@redhat.com>2017-08-02 19:09:19 +0300
committerIngo Molnar <mingo@kernel.org>2017-08-10 21:16:44 +0300
commit2ffd9e33ce4af4e8cfa3e17bf493defe8474e2eb (patch)
tree47f4afe37d6bf0e6e0219ab1b08ca45fc692aa47 /drivers/hv/Kconfig
parent7415aea6072bab15969b6c3c5b2a193d88095326 (diff)
downloadlinux-2ffd9e33ce4af4e8cfa3e17bf493defe8474e2eb.tar.xz
x86/hyper-v: Use hypercall for remote TLB flush
Hyper-V host can suggest us to use hypercall for doing remote TLB flush, this is supposed to work faster than IPIs. Implementation details: to do HvFlushVirtualAddress{Space,List} hypercalls we need to put the input somewhere in memory and we don't really want to have memory allocation on each call so we pre-allocate per cpu memory areas on boot. pv_ops patching is happening very early so we need to separate hyperv_setup_mmu_ops() and hyper_alloc_mmu(). It is possible and easy to implement local TLB flushing too and there is even a hint for that. However, I don't see a room for optimization on the host side as both hypercall and native tlb flush will result in vmexit. The hint is also not set on modern Hyper-V versions. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Stephen Hemminger <sthemmin@microsoft.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jork Loeser <Jork.Loeser@microsoft.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Simon Xiao <sixiao@microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: devel@linuxdriverproject.org Link: http://lkml.kernel.org/r/20170802160921.21791-8-vkuznets@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers/hv/Kconfig')
-rw-r--r--drivers/hv/Kconfig1
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig
index c29cd5387a35..50b89ea0e60f 100644
--- a/drivers/hv/Kconfig
+++ b/drivers/hv/Kconfig
@@ -3,6 +3,7 @@ menu "Microsoft Hyper-V guest support"
config HYPERV
tristate "Microsoft Hyper-V client drivers"
depends on X86 && ACPI && PCI && X86_LOCAL_APIC && HYPERVISOR_GUEST
+ select PARAVIRT
help
Select this option to run Linux as a Hyper-V client operating
system.