Re: [PATCH v7 4/8] KVM: x86/mmu: Migrate to __kvm_follow_pfn
From: Isaku Yamahata <hidden>
Date: 2023-07-06 01:54:59
Also in:
kvm, kvmarm, linuxppc-dev, lkml
On Tue, Jul 04, 2023 at 04:50:49PM +0900, David Stevens [off-list ref] wrote:
quoted hunk ↗ jump to hunk
From: David Stevens <redacted> Migrate from __gfn_to_pfn_memslot to __kvm_follow_pfn. Signed-off-by: David Stevens <redacted> --- arch/x86/kvm/mmu/mmu.c | 35 +++++++++++++++++++++++++---------- 1 file changed, 25 insertions(+), 10 deletions(-)diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index ec169f5c7dce..e44ab512c3a1 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c@@ -4296,7 +4296,12 @@ void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work) static int __kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) { struct kvm_memory_slot *slot = fault->slot; - bool async; + struct kvm_follow_pfn foll = { + .slot = slot, + .gfn = fault->gfn, + .flags = FOLL_GET | (fault->write ? FOLL_WRITE : 0), + .allow_write_mapping = true, + }; /* * Retry the page fault if the gfn hit a memslot that is being deleted@@ -4325,12 +4330,14 @@ static int __kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault return RET_PF_EMULATE; } - async = false; - fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, false, &async, - fault->write, &fault->map_writable, - &fault->hva); - if (!async) - return RET_PF_CONTINUE; /* *pfn has correct page already */ + foll.flags |= FOLL_NOWAIT; + fault->pfn = __kvm_follow_pfn(&foll); + + if (!is_error_noslot_pfn(fault->pfn))
We have pfn in struct kvm_follow_pfn as output. Can we make __kvm_follow_pfn() return int instead of kvm_pfn_t? KVM_PFN_* seems widely used, though.
quoted hunk ↗ jump to hunk
+ goto success; + + if (fault->pfn != KVM_PFN_ERR_NEEDS_IO) + return RET_PF_CONTINUE; if (!fault->prefetch && kvm_can_do_async_pf(vcpu)) { trace_kvm_try_async_get_page(fault->addr, fault->gfn);@@ -4348,9 +4355,17 @@ static int __kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault * to wait for IO. Note, gup always bails if it is unable to quickly * get a page and a fatal signal, i.e. SIGKILL, is pending. */ - fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, true, NULL, - fault->write, &fault->map_writable, - &fault->hva); + foll.flags |= FOLL_INTERRUPTIBLE; + foll.flags &= ~FOLL_NOWAIT; + fault->pfn = __kvm_follow_pfn(&foll); + + if (!is_error_noslot_pfn(fault->pfn)) + goto success; + + return RET_PF_CONTINUE; +success: + fault->hva = foll.hva; + fault->map_writable = foll.writable; return RET_PF_CONTINUE; }-- 2.41.0.255.g8b1d071c50-goog
-- Isaku Yamahata [off-list ref] _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel