mirror of
https://github.com/torvalds/linux.git
synced 2024-12-02 00:51:44 +00:00
9ed3bf4112
Refactor Hyper-V's range-based TLB flushing API to take a gfn+nr_pages pair instead of a struct, and bury said struct in Hyper-V specific code. Passing along two params generates much better code for the common case where KVM is _not_ running on Hyper-V, as forwarding the flush on to Hyper-V's hv_flush_remote_tlbs_range() from kvm_flush_remote_tlbs_range() becomes a tail call. Cc: David Matlack <dmatlack@google.com> Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Link: https://lore.kernel.org/r/20230405003133.419177-3-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
125 lines
3.1 KiB
C
125 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* KVM L1 hypervisor optimizations on Hyper-V.
|
|
*/
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/kvm_host.h>
|
|
#include <asm/mshyperv.h>
|
|
|
|
#include "hyperv.h"
|
|
#include "kvm_onhyperv.h"
|
|
|
|
struct kvm_hv_tlb_range {
|
|
u64 start_gfn;
|
|
u64 pages;
|
|
};
|
|
|
|
static int kvm_fill_hv_flush_list_func(struct hv_guest_mapping_flush_list *flush,
|
|
void *data)
|
|
{
|
|
struct kvm_hv_tlb_range *range = data;
|
|
|
|
return hyperv_fill_flush_guest_mapping_list(flush, range->start_gfn,
|
|
range->pages);
|
|
}
|
|
|
|
static inline int hv_remote_flush_root_tdp(hpa_t root_tdp,
|
|
struct kvm_hv_tlb_range *range)
|
|
{
|
|
if (range)
|
|
return hyperv_flush_guest_mapping_range(root_tdp,
|
|
kvm_fill_hv_flush_list_func, (void *)range);
|
|
else
|
|
return hyperv_flush_guest_mapping(root_tdp);
|
|
}
|
|
|
|
static int __hv_flush_remote_tlbs_range(struct kvm *kvm,
|
|
struct kvm_hv_tlb_range *range)
|
|
{
|
|
struct kvm_arch *kvm_arch = &kvm->arch;
|
|
struct kvm_vcpu *vcpu;
|
|
int ret = 0, nr_unique_valid_roots;
|
|
unsigned long i;
|
|
hpa_t root;
|
|
|
|
spin_lock(&kvm_arch->hv_root_tdp_lock);
|
|
|
|
if (!VALID_PAGE(kvm_arch->hv_root_tdp)) {
|
|
nr_unique_valid_roots = 0;
|
|
|
|
/*
|
|
* Flush all valid roots, and see if all vCPUs have converged
|
|
* on a common root, in which case future flushes can skip the
|
|
* loop and flush the common root.
|
|
*/
|
|
kvm_for_each_vcpu(i, vcpu, kvm) {
|
|
root = vcpu->arch.hv_root_tdp;
|
|
if (!VALID_PAGE(root) || root == kvm_arch->hv_root_tdp)
|
|
continue;
|
|
|
|
/*
|
|
* Set the tracked root to the first valid root. Keep
|
|
* this root for the entirety of the loop even if more
|
|
* roots are encountered as a low effort optimization
|
|
* to avoid flushing the same (first) root again.
|
|
*/
|
|
if (++nr_unique_valid_roots == 1)
|
|
kvm_arch->hv_root_tdp = root;
|
|
|
|
if (!ret)
|
|
ret = hv_remote_flush_root_tdp(root, range);
|
|
|
|
/*
|
|
* Stop processing roots if a failure occurred and
|
|
* multiple valid roots have already been detected.
|
|
*/
|
|
if (ret && nr_unique_valid_roots > 1)
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* The optimized flush of a single root can't be used if there
|
|
* are multiple valid roots (obviously).
|
|
*/
|
|
if (nr_unique_valid_roots > 1)
|
|
kvm_arch->hv_root_tdp = INVALID_PAGE;
|
|
} else {
|
|
ret = hv_remote_flush_root_tdp(kvm_arch->hv_root_tdp, range);
|
|
}
|
|
|
|
spin_unlock(&kvm_arch->hv_root_tdp_lock);
|
|
return ret;
|
|
}
|
|
|
|
int hv_flush_remote_tlbs_range(struct kvm *kvm, gfn_t start_gfn, gfn_t nr_pages)
|
|
{
|
|
struct kvm_hv_tlb_range range = {
|
|
.start_gfn = start_gfn,
|
|
.pages = nr_pages,
|
|
};
|
|
|
|
return __hv_flush_remote_tlbs_range(kvm, &range);
|
|
}
|
|
EXPORT_SYMBOL_GPL(hv_flush_remote_tlbs_range);
|
|
|
|
int hv_flush_remote_tlbs(struct kvm *kvm)
|
|
{
|
|
return __hv_flush_remote_tlbs_range(kvm, NULL);
|
|
}
|
|
EXPORT_SYMBOL_GPL(hv_flush_remote_tlbs);
|
|
|
|
void hv_track_root_tdp(struct kvm_vcpu *vcpu, hpa_t root_tdp)
|
|
{
|
|
struct kvm_arch *kvm_arch = &vcpu->kvm->arch;
|
|
|
|
if (kvm_x86_ops.flush_remote_tlbs == hv_flush_remote_tlbs) {
|
|
spin_lock(&kvm_arch->hv_root_tdp_lock);
|
|
vcpu->arch.hv_root_tdp = root_tdp;
|
|
if (root_tdp != kvm_arch->hv_root_tdp)
|
|
kvm_arch->hv_root_tdp = INVALID_PAGE;
|
|
spin_unlock(&kvm_arch->hv_root_tdp_lock);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(hv_track_root_tdp);
|