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2017-10-10x86/hyperv: Fix hypercalls with extended CPU ranges for TLB flushingMarcelo Henrique Cerri
Do not consider the fixed size of hv_vp_set when passing the variable header size to hv_do_rep_hypercall(). The Hyper-V hypervisor specification states that for a hypercall with a variable header only the size of the variable portion should be supplied via the input control. For HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX/LIST_EX calls that means the fixed portion of hv_vp_set should not be considered. That fixes random failures of some applications that are unexpectedly killed with SIGBUS or SIGSEGV. Signed-off-by: Marcelo Henrique Cerri <marcelo.cerri@canonical.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jork Loeser <Jork.Loeser@microsoft.com> Cc: Josh Poulson <jopoulso@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: Stephen Hemminger <sthemmin@microsoft.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: devel@linuxdriverproject.org Fixes: 628f54cc6451 ("x86/hyper-v: Support extended CPU ranges for TLB flush hypercalls") Link: http://lkml.kernel.org/r/1507210469-29065-1-git-send-email-marcelo.cerri@canonical.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-10x86/hyperv: Don't use percpu areas for pcpu_flush/pcpu_flush_ex structuresVitaly Kuznetsov
hv_do_hypercall() does virt_to_phys() translation and with some configs (CONFIG_SLAB) this doesn't work for percpu areas, we pass wrong memory to hypervisor and get #GP. We could use working slow_virt_to_phys() instead but doing so kills the performance. Move pcpu_flush/pcpu_flush_ex structures out of percpu areas and allocate memory on first call. The additional level of indirection gives us a small performance penalty, in future we may consider introducing hypercall functions which avoid virt_to_phys() conversion and cache physical addresses of pcpu_flush/pcpu_flush_ex structures somewhere. Reported-by: Simon Xiao <sixiao@microsoft.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Dexuan Cui <decui@microsoft.com> 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: Stephen Hemminger <sthemmin@microsoft.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: devel@linuxdriverproject.org Link: http://lkml.kernel.org/r/20171005113924.28021-1-vkuznets@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-10x86/hyperv: Clear vCPU banks between calls to avoid flushing unneeded vCPUsVitaly Kuznetsov
hv_flush_pcpu_ex structures are not cleared between calls for performance reasons (they're variable size up to PAGE_SIZE each) but we must clear hv_vp_set.bank_contents part of it to avoid flushing unneeded vCPUs. The rest of the structure is formed correctly. To do the clearing in an efficient way stash the maximum possible vCPU number (this may differ from Linux CPU id). Reported-by: Jork Loeser <Jork.Loeser@microsoft.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: devel@linuxdriverproject.org Link: http://lkml.kernel.org/r/20171006154854.18092-1-vkuznets@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-31tracing/hyper-v: Trace hyperv_mmu_flush_tlb_others()Vitaly Kuznetsov
Add Hyper-V tracing subsystem and trace hyperv_mmu_flush_tlb_others(). Tracing is done the same way we do xen_mmu_flush_tlb_others(). Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Stephen Hemminger <sthemmin@microsoft.com> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> 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: Thomas Gleixner <tglx@linutronix.de> Cc: devel@linuxdriverproject.org Link: http://lkml.kernel.org/r/20170802160921.21791-10-vkuznets@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-31x86/hyper-v: Support extended CPU ranges for TLB flush hypercallsVitaly Kuznetsov
Hyper-V hosts may support more than 64 vCPUs, we need to use HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX/LIST_EX hypercalls in this case. 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/20170802160921.21791-9-vkuznets@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-10x86/hyper-v: Use hypercall for remote TLB flushVitaly Kuznetsov
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>