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| author | Kalesh Singh <kaleshsingh@google.com> | 2022-04-21 00:42:53 +0300 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2022-04-28 22:53:13 +0300 |
| commit | f922c13e778d6d5343d4576be785a8204c595113 (patch) | |
| tree | 6ab6e124c71ef01dc5df7ea384b8087d9c418473 /arch/arm64/kvm/hyp/nvhe/hyp-main.c | |
| parent | 92abe0f81e1385afd8f1dc66206b5be9a514899b (diff) | |
| download | linux-f922c13e778d6d5343d4576be785a8204c595113.tar.xz | |
KVM: arm64: Introduce pkvm_alloc_private_va_range()
pkvm_hyp_alloc_private_va_range() can be used to reserve private VA ranges
in the pKVM nVHE hypervisor. Allocations are aligned based on the order of
the requested size.
This will be used to implement stack guard pages for pKVM nVHE hypervisor
(in a subsequent patch in the series).
Credits to Quentin Perret <qperret@google.com> for the idea of moving
private VA allocation out of __pkvm_create_private_mapping()
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220420214317.3303360-3-kaleshsingh@google.com
Diffstat (limited to 'arch/arm64/kvm/hyp/nvhe/hyp-main.c')
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/hyp-main.c | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index 5e2197db0d32..3cea4b6ac23e 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -160,7 +160,23 @@ static void handle___pkvm_create_private_mapping(struct kvm_cpu_context *host_ct DECLARE_REG(size_t, size, host_ctxt, 2); DECLARE_REG(enum kvm_pgtable_prot, prot, host_ctxt, 3); - cpu_reg(host_ctxt, 1) = __pkvm_create_private_mapping(phys, size, prot); + /* + * __pkvm_create_private_mapping() populates a pointer with the + * hypervisor start address of the allocation. + * + * However, handle___pkvm_create_private_mapping() hypercall crosses the + * EL1/EL2 boundary so the pointer would not be valid in this context. + * + * Instead pass the allocation address as the return value (or return + * ERR_PTR() on failure). + */ + unsigned long haddr; + int err = __pkvm_create_private_mapping(phys, size, prot, &haddr); + + if (err) + haddr = (unsigned long)ERR_PTR(err); + + cpu_reg(host_ctxt, 1) = haddr; } static void handle___pkvm_prot_finalize(struct kvm_cpu_context *host_ctxt) |