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authorDavid Brazdil <dbrazdil@google.com>2020-12-02 18:41:13 +0000
committerMarc Zyngier <maz@kernel.org>2020-12-04 10:08:34 +0000
commitd084ecc5c72811e7231838f7c128bfcc7f8d2889 (patch)
tree30e74b89467e8cabcc35003e7f73295f679206b4
parenteeeee7193df015074c8302381356e8e617a5e2b0 (diff)
downloadlinux-d084ecc5c72811e7231838f7c128bfcc7f8d2889.tar.bz2
KVM: arm64: Add offset for hyp VA <-> PA conversion
Add a host-initialized constant to KVM nVHE hyp code for converting between EL2 linear map virtual addresses and physical addresses. Also add `__hyp_pa` macro that performs the conversion. Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201202184122.26046-18-dbrazdil@google.com
-rw-r--r--arch/arm64/kvm/hyp/nvhe/psci-relay.c3
-rw-r--r--arch/arm64/kvm/va_layout.c30
2 files changed, 30 insertions, 3 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/psci-relay.c b/arch/arm64/kvm/hyp/nvhe/psci-relay.c
index 61375d4571c2..70b42f433449 100644
--- a/arch/arm64/kvm/hyp/nvhe/psci-relay.c
+++ b/arch/arm64/kvm/hyp/nvhe/psci-relay.c
@@ -18,6 +18,9 @@
/* Config options set by the host. */
__ro_after_init u32 kvm_host_psci_version;
__ro_after_init struct psci_0_1_function_ids kvm_host_psci_0_1_function_ids;
+__ro_after_init s64 hyp_physvirt_offset;
+
+#define __hyp_pa(x) ((phys_addr_t)((x)) + hyp_physvirt_offset)
static u64 get_psci_func_id(struct kvm_cpu_context *host_ctxt)
{
diff --git a/arch/arm64/kvm/va_layout.c b/arch/arm64/kvm/va_layout.c
index d61117805de0..16aa8615c279 100644
--- a/arch/arm64/kvm/va_layout.c
+++ b/arch/arm64/kvm/va_layout.c
@@ -24,6 +24,30 @@ static u64 tag_val;
static u64 va_mask;
/*
+ * Compute HYP VA by using the same computation as kern_hyp_va().
+ */
+static u64 __early_kern_hyp_va(u64 addr)
+{
+ addr &= va_mask;
+ addr |= tag_val << tag_lsb;
+ return addr;
+}
+
+/*
+ * Store a hyp VA <-> PA offset into a hyp-owned variable.
+ */
+static void init_hyp_physvirt_offset(void)
+{
+ extern s64 kvm_nvhe_sym(hyp_physvirt_offset);
+ u64 kern_va, hyp_va;
+
+ /* Compute the offset from the hyp VA and PA of a random symbol. */
+ kern_va = (u64)kvm_ksym_ref(__hyp_text_start);
+ hyp_va = __early_kern_hyp_va(kern_va);
+ CHOOSE_NVHE_SYM(hyp_physvirt_offset) = (s64)__pa(kern_va) - (s64)hyp_va;
+}
+
+/*
* We want to generate a hyp VA with the following format (with V ==
* vabits_actual):
*
@@ -54,6 +78,8 @@ __init void kvm_compute_layout(void)
tag_val |= get_random_long() & GENMASK_ULL(vabits_actual - 2, tag_lsb);
}
tag_val >>= tag_lsb;
+
+ init_hyp_physvirt_offset();
}
static u32 compute_instruction(int n, u32 rd, u32 rn)
@@ -151,9 +177,7 @@ void kvm_patch_vector_branch(struct alt_instr *alt,
/*
* Compute HYP VA by using the same computation as kern_hyp_va()
*/
- addr = (uintptr_t)kvm_ksym_ref(__kvm_hyp_vector);
- addr &= va_mask;
- addr |= tag_val << tag_lsb;
+ addr = __early_kern_hyp_va((u64)kvm_ksym_ref(__kvm_hyp_vector));
/* Use PC[10:7] to branch to the same vector in KVM */
addr |= ((u64)origptr & GENMASK_ULL(10, 7));