[PATCH v2 13/24] kvm: arm64: Add offset for hyp VA <-> PA conversion
From: David Brazdil <hidden>
Date: 2020-11-16 20:44:12
Also in:
kvmarm, lkml
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
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 <redacted> --- arch/arm64/kvm/hyp/nvhe/psci-relay.c | 3 +++ arch/arm64/kvm/va_layout.c | 30 +++++++++++++++++++++++++--- 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 d75d3f896bfd..1583b63322c4 100644
--- a/arch/arm64/kvm/hyp/nvhe/psci-relay.c
+++ b/arch/arm64/kvm/hyp/nvhe/psci-relay.c@@ -16,6 +16,9 @@ /* Config options set by the host. */ u32 __ro_after_init kvm_host_psci_version = PSCI_VERSION(0, 0); u32 __ro_after_init kvm_host_psci_function_id[PSCI_FN_MAX]; +s64 __ro_after_init 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 e0404bcab019..744a0d998ad3 100644
--- a/arch/arm64/kvm/va_layout.c
+++ b/arch/arm64/kvm/va_layout.c@@ -22,6 +22,30 @@ static u8 tag_lsb; 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):
@@ -53,6 +77,8 @@ __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)
@@ -150,9 +176,7 @@ 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));
--
2.29.2.299.gdc1121823c-goog
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