From 2ffd9e33ce4af4e8cfa3e17bf493defe8474e2eb Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Wed, 2 Aug 2017 18:09:19 +0200 Subject: 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 Reviewed-by: Andy Shevchenko Reviewed-by: Stephen Hemminger Cc: Andy Lutomirski Cc: Haiyang Zhang Cc: Jork Loeser Cc: K. Y. Srinivasan Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Simon Xiao Cc: Steven Rostedt Cc: Thomas Gleixner Cc: devel@linuxdriverproject.org Link: http://lkml.kernel.org/r/20170802160921.21791-8-vkuznets@redhat.com Signed-off-by: Ingo Molnar --- arch/x86/include/asm/mshyperv.h | 3 +++ arch/x86/include/uapi/asm/hyperv.h | 7 +++++++ 2 files changed, 10 insertions(+) (limited to 'arch/x86/include') diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h index efd2f80d3353..0d4b01c5e438 100644 --- a/arch/x86/include/asm/mshyperv.h +++ b/arch/x86/include/asm/mshyperv.h @@ -307,6 +307,8 @@ static inline int hv_cpu_number_to_vp_number(int cpu_number) } void hyperv_init(void); +void hyperv_setup_mmu_ops(void); +void hyper_alloc_mmu(void); void hyperv_report_panic(struct pt_regs *regs); bool hv_is_hypercall_page_setup(void); void hyperv_cleanup(void); @@ -314,6 +316,7 @@ void hyperv_cleanup(void); static inline void hyperv_init(void) {} static inline bool hv_is_hypercall_page_setup(void) { return false; } static inline void hyperv_cleanup(void) {} +static inline void hyperv_setup_mmu_ops(void) {} #endif /* CONFIG_HYPERV */ #ifdef CONFIG_HYPERV_TSCPAGE diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h index 127ddadee1a5..a6fdd3b82b4a 100644 --- a/arch/x86/include/uapi/asm/hyperv.h +++ b/arch/x86/include/uapi/asm/hyperv.h @@ -242,6 +242,8 @@ (~((1ull << HV_X64_MSR_HYPERCALL_PAGE_ADDRESS_SHIFT) - 1)) /* Declare the various hypercall operations. */ +#define HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE 0x0002 +#define HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST 0x0003 #define HVCALL_NOTIFY_LONG_SPIN_WAIT 0x0008 #define HVCALL_POST_MESSAGE 0x005c #define HVCALL_SIGNAL_EVENT 0x005d @@ -259,6 +261,11 @@ #define HV_PROCESSOR_POWER_STATE_C2 2 #define HV_PROCESSOR_POWER_STATE_C3 3 +#define HV_FLUSH_ALL_PROCESSORS BIT(0) +#define HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES BIT(1) +#define HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY BIT(2) +#define HV_FLUSH_USE_EXTENDED_RANGE_FORMAT BIT(3) + /* hypercall status code */ #define HV_STATUS_SUCCESS 0 #define HV_STATUS_INVALID_HYPERCALL_CODE 2 -- cgit v1.2.3