Ben Gardon bgardon@google.com writes:
Separate the functions for generating MMIO page table entries from the function that inserts them into the paging structure. This refactoring will facilitate changes to the MMU sychronization model to use atomic compare / exchanges (which are not guaranteed to succeed) instead of a monolithic MMU lock.
No functional change expected.
Tested by running kvm-unit-tests on an Intel Haswell machine. This commit introduced no new failures.
This commit can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2359
Signed-off-by: Ben Gardon bgardon@google.com Reviewed-by: Oliver Upton oupton@google.com Reviewed-by: Peter Shier pshier@google.com
arch/x86/kvm/mmu/mmu.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index a9c593dec49bf..b81010d0edae1 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -451,9 +451,9 @@ static u64 get_mmio_spte_generation(u64 spte) return gen; } -static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn,
unsigned int access)+static u64 make_mmio_spte(struct kvm_vcpu *vcpu, u64 gfn, unsigned int access) {
Unneded newline.
u64 gen = kvm_vcpu_memslots(vcpu)->generation & MMIO_SPTE_GEN_MASK; u64 mask = generation_mmio_spte_mask(gen); u64 gpa = gfn << PAGE_SHIFT; @@ -464,6 +464,17 @@ static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn, mask |= (gpa & shadow_nonpresent_or_rsvd_mask) << shadow_nonpresent_or_rsvd_mask_len;
- return mask;
+}
+static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn,
unsigned int access)+{
- u64 mask = make_mmio_spte(vcpu, gfn, access);
- unsigned int gen = get_mmio_spte_generation(mask);
- access = mask & ACC_ALL;
- trace_mark_mmio_spte(sptep, gfn, access, gen);
'access' and 'gen' are only being used for tracing, would it rather make sense to rename&move it to the newly introduced make_mmio_spte()? Or do we actually need tracing for both?
Also, I dislike re-purposing function parameters.
mmu_spte_set(sptep, mask); }