linux/arch/x86/kvm/kvm_onhyperv.c
Vineeth Pillai 3c86c0d3db KVM: x86: hyper-v: Move the remote TLB flush logic out of vmx
Currently the remote TLB flush logic is specific to VMX.
Move it to a common place so that SVM can use it as well.

Signed-off-by: Vineeth Pillai <viremana@linux.microsoft.com>
Message-Id: <4f4e4ca19778437dae502f44363a38e99e3ef5d1.1622730232.git.viremana@linux.microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:36 -04:00

94 lines
2.3 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* KVM L1 hypervisor optimizations on Hyper-V.
*/
#include <linux/kvm_host.h>
#include <asm/mshyperv.h>
#include "hyperv.h"
#include "kvm_onhyperv.h"
static int kvm_fill_hv_flush_list_func(struct hv_guest_mapping_flush_list *flush,
void *data)
{
struct kvm_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_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);
}
int hv_remote_flush_tlb_with_range(struct kvm *kvm,
struct kvm_tlb_range *range)
{
struct kvm_arch *kvm_arch = &kvm->arch;
struct kvm_vcpu *vcpu;
int ret = 0, i, nr_unique_valid_roots;
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;
}
EXPORT_SYMBOL_GPL(hv_remote_flush_tlb_with_range);
int hv_remote_flush_tlb(struct kvm *kvm)
{
return hv_remote_flush_tlb_with_range(kvm, NULL);
}
EXPORT_SYMBOL_GPL(hv_remote_flush_tlb);