diff options
| author | Anup Patel <apatel@ventanamicro.com> | 2022-05-09 10:44:05 +0530 |
|---|---|---|
| committer | Anup Patel <anup@brainfault.org> | 2022-05-20 09:09:15 +0530 |
| commit | 13acfec2dbccfafff3331a3810cd7dde2fb16891 (patch) | |
| tree | 961a009272dbc57463373abe49439abc7c22694b /arch/riscv/kvm/mmu.c | |
| parent | 486a38429498eef5acac90aeab68a1c3fa653a21 (diff) | |
RISC-V: KVM: Add remote HFENCE functions based on VCPU requests
The generic KVM has support for VCPU requests which can be used
to do arch-specific work in the run-loop. We introduce remote
HFENCE functions which will internally use VCPU requests instead
of host SBI calls.
Advantages of doing remote HFENCEs as VCPU requests are:
1) Multiple VCPUs of a Guest may be running on different Host CPUs
so it is not always possible to determine the Host CPU mask for
doing Host SBI call. For example, when VCPU X wants to do HFENCE
on VCPU Y, it is possible that VCPU Y is blocked or in user-space
(i.e. vcpu->cpu < 0).
2) To support nested virtualization, we will be having a separate
shadow G-stage for each VCPU and a common host G-stage for the
entire Guest/VM. The VCPU requests based remote HFENCEs helps
us easily synchronize the common host G-stage and shadow G-stage
of each VCPU without any additional IPI calls.
This is also a preparatory patch for upcoming nested virtualization
support where we will be having a shadow G-stage page table for
each Guest VCPU.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
Diffstat (limited to 'arch/riscv/kvm/mmu.c')
| -rw-r--r-- | arch/riscv/kvm/mmu.c | 33 |
1 files changed, 18 insertions, 15 deletions
diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c index 1e07603c905b..1c00695ebee7 100644 --- a/arch/riscv/kvm/mmu.c +++ b/arch/riscv/kvm/mmu.c @@ -18,7 +18,6 @@ #include <asm/csr.h> #include <asm/page.h> #include <asm/pgtable.h> -#include <asm/sbi.h> #ifdef CONFIG_64BIT static unsigned long gstage_mode = (HGATP_MODE_SV39X4 << HGATP_MODE_SHIFT); @@ -73,13 +72,25 @@ static int gstage_page_size_to_level(unsigned long page_size, u32 *out_level) return -EINVAL; } -static int gstage_level_to_page_size(u32 level, unsigned long *out_pgsize) +static int gstage_level_to_page_order(u32 level, unsigned long *out_pgorder) { if (gstage_pgd_levels < level) return -EINVAL; - *out_pgsize = 1UL << (12 + (level * gstage_index_bits)); + *out_pgorder = 12 + (level * gstage_index_bits); + return 0; +} +static int gstage_level_to_page_size(u32 level, unsigned long *out_pgsize) +{ + int rc; + unsigned long page_order = PAGE_SHIFT; + + rc = gstage_level_to_page_order(level, &page_order); + if (rc) + return rc; + + *out_pgsize = BIT(page_order); return 0; } @@ -114,21 +125,13 @@ static bool gstage_get_leaf_entry(struct kvm *kvm, gpa_t addr, static void gstage_remote_tlb_flush(struct kvm *kvm, u32 level, gpa_t addr) { - unsigned long size = PAGE_SIZE; - struct kvm_vmid *vmid = &kvm->arch.vmid; + unsigned long order = PAGE_SHIFT; - if (gstage_level_to_page_size(level, &size)) + if (gstage_level_to_page_order(level, &order)) return; - addr &= ~(size - 1); + addr &= ~(BIT(order) - 1); - /* - * TODO: Instead of cpu_online_mask, we should only target CPUs - * where the Guest/VM is running. - */ - preempt_disable(); - sbi_remote_hfence_gvma_vmid(cpu_online_mask, addr, size, - READ_ONCE(vmid->vmid)); - preempt_enable(); + kvm_riscv_hfence_gvma_vmid_gpa(kvm, -1UL, 0, addr, BIT(order), order); } static int gstage_set_pte(struct kvm *kvm, u32 level, |