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| author | Sean Christopherson <seanjc@google.com> | 2024-10-10 11:23:24 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2024-10-25 12:57:59 -0400 |
| commit | ef7db98e477f4b379fac3131bf94c33774c4a211 (patch) | |
| tree | cdfde30a99bcfaafa6eaed3b462dcedea02ee1b1 | |
| parent | 5488499f9c645d6c1ffe151be196df38ee5a56b4 (diff) | |
| download | linux-ef7db98e477f4b379fac3131bf94c33774c4a211.tar.gz linux-ef7db98e477f4b379fac3131bf94c33774c4a211.tar.bz2 linux-ef7db98e477f4b379fac3131bf94c33774c4a211.zip | |
KVM: Use NULL for struct page pointer to indicate mremapped memory
Drop yet another unnecessary magic page value from KVM, as there's zero
reason to use a poisoned pointer to indicate "no page". If KVM uses a
NULL page pointer, the kernel will explode just as quickly as if KVM uses
a poisoned pointer. Never mind the fact that such usage would be a
blatant and egregious KVM bug.
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20241010182427.1434605-23-seanjc@google.com>
| -rw-r--r-- | include/linux/kvm_host.h | 4 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 4 |
2 files changed, 2 insertions, 6 deletions
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 2c9eb472f059..cd6f5cc1930f 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -273,16 +273,12 @@ enum { READING_SHADOW_PAGE_TABLES, }; -#define KVM_UNMAPPED_PAGE ((void *) 0x500 + POISON_POINTER_DELTA) - struct kvm_host_map { /* * Only valid if the 'pfn' is managed by the host kernel (i.e. There is * a 'struct page' for it. When using mem= kernel parameter some memory * can be used as guest memory but they are not managed by host * kernel). - * If 'pfn' is not managed by the host kernel, this field is - * initialized to KVM_UNMAPPED_PAGE. */ struct page *page; void *hva; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 4074f49eb3f1..c20386a8aa3e 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -3061,7 +3061,7 @@ void kvm_release_pfn(kvm_pfn_t pfn, bool dirty) int kvm_vcpu_map(struct kvm_vcpu *vcpu, gfn_t gfn, struct kvm_host_map *map) { - map->page = KVM_UNMAPPED_PAGE; + map->page = NULL; map->hva = NULL; map->gfn = gfn; @@ -3087,7 +3087,7 @@ void kvm_vcpu_unmap(struct kvm_vcpu *vcpu, struct kvm_host_map *map, bool dirty) if (!map->hva) return; - if (map->page != KVM_UNMAPPED_PAGE) + if (map->page) kunmap(map->page); #ifdef CONFIG_HAS_IOMEM else |