Messages in this thread | | | From | Tianyu Lan <> | Subject | Re: [RFC Patch 1/3] X86/Hyper-V: Add flush HvFlushGuestPhysicalAddressSpace hypercall support | Date | Wed, 6 Jun 2018 05:36:29 +0000 |
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Hi Michael: Thanks for your review.
On 6/6/2018 12:59 AM, Michael Kelley (EOSG) wrote: >> -----Original Message----- >> From: linux-kernel-owner@vger.kernel.org <linux-kernel-owner@vger.kernel.org> On Behalf >> Of Tianyu Lan >> Sent: Monday, June 4, 2018 2:08 AM >> Cc: Tianyu Lan <Tianyu.Lan@microsoft.com>; KY Srinivasan <kys@microsoft.com>; Haiyang >> Zhang <haiyangz@microsoft.com>; Stephen Hemminger <sthemmin@microsoft.com>; >> tglx@linutronix.de; mingo@redhat.com; hpa@zytor.com; x86@kernel.org; >> pbonzini@redhat.com; rkrcmar@redhat.com; devel@linuxdriverproject.org; linux- >> kernel@vger.kernel.org; kvm@vger.kernel.org; vkuznets@redhat.com >> Subject: [RFC Patch 1/3] X86/Hyper-V: Add flush HvFlushGuestPhysicalAddressSpace hypercall >> support >> >> Hyper-V provides a pv hypercall HvFlushGuestPhysicalAddressSpace to flush >> nested VM address space mapping in l1 hypervisor and it's to reduce overhead >> of flushing ept tlb among vcpus. This patch is to implement it. >> >> Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> >> --- >> diff --git a/arch/x86/hyperv/nested.c b/arch/x86/hyperv/nested.c >> new file mode 100644 >> index 000000000000..17f7c288eccc >> --- /dev/null >> +++ b/arch/x86/hyperv/nested.c >> +#include <linux/types.h> >> +#include <asm/hyperv-tlfs.h> >> +#include <asm/mshyperv.h> >> +#include <asm/tlbflush.h> >> + >> +int hyperv_flush_guest_mapping(u64 as) >> +{ >> + struct hv_guest_mapping_flush **flush_pcpu; >> + struct hv_guest_mapping_flush *flush; >> + u64 status = U64_MAX; > > Initializing status to U64_MAX doesn't seem necessary. > >> + unsigned long flags; >> + int ret = -EFAULT; >> + >> + if (!hv_hypercall_pg) >> + goto fault; >> + >> + local_irq_save(flags); >> + >> + flush_pcpu = (struct hv_guest_mapping_flush **) >> + this_cpu_ptr(hyperv_pcpu_input_arg); >> + >> + flush = *flush_pcpu; >> + >> + if (unlikely(!flush)) { >> + local_irq_restore(flags); >> + goto fault; >> + } >> + >> + flush->address_space = as; >> + flush->flags = 0; >> + >> + status = hv_do_hypercall(HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE, >> + flush, NULL); >> + local_irq_restore(flags); >> + >> + if (!(status & HV_HYPERCALL_RESULT_MASK)) >> + ret = 0; >> + >> +fault: >> + return ret; >> +} >> +EXPORT_SYMBOL_GPL(hyperv_flush_guest_mapping); >> diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h >> index b8c89265baf0..53bbeb08faea 100644 >> --- a/arch/x86/include/asm/hyperv-tlfs.h >> +++ b/arch/x86/include/asm/hyperv-tlfs.h >> @@ -309,6 +309,7 @@ struct ms_hyperv_tsc_page { >> #define HV_X64_MSR_REENLIGHTENMENT_CONTROL 0x40000106 >> >> /* Nested features (CPUID 0x4000000A) EAX */ >> +#define HV_X64_NESTED_GUSET_MAPPING_FLUSH BIT(18) > > The #define name is misspelled. "_GUSET_" should be "_GUEST_". > And the matching usage in patch 3/3 will need to be updated as well. > > Michael >
Nice catch! Will update.
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