admin/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2025-12-07 20:06:24 +00:00
Code Issues Packages Projects Releases Wiki Activity

KVM: TDX: WARN if mirror SPTE doesn't have full RWX when creating S-EPT mapping

Browse Source 
Pass in the mirror_spte to kvm_x86_ops.set_external_spte() to provide
symmetry with .remove_external_spte(), and assert in TDX that the mirror
SPTE is shadow-present with full RWX permissions (the TDX-Module doesn't
allow the hypervisor to control protections).

Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Tested-by: Yan Zhao <yan.y.zhao@intel.com>
Tested-by: Kai Huang <kai.huang@intel.com>
Link: https://patch.msgid.link/20251030200951.3402865-13-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
This commit is contained in:
Sean Christopherson
2025-10-30 13:09:35 -07:00
parent 7139c86065
commit b9d5cf6de0
3 changed files with 7 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
arch/x86/include/asm/kvm_host.h
View File

@@ -1848,7 +1848,7 @@ struct kvm_x86_ops {
void *external_spt);
/* Update the external page table from spte getting set. */
int (*set_external_spte)(struct kvm *kvm, gfn_t gfn, enum pg_level level,
kvm_pfn_t pfn_for_gfn);
u64 mirror_spte);
/* Update external page tables for page table about to be freed. */
int (*free_external_spt)(struct kvm *kvm, gfn_t gfn, enum pg_level level,

3
arch/x86/kvm/mmu/tdp_mmu.c
View File

@@ -515,7 +515,6 @@ static int __must_check set_external_spte_present(struct kvm *kvm, tdp_ptep_t sp
bool was_present = is_shadow_present_pte(old_spte);
bool is_present = is_shadow_present_pte(new_spte);
bool is_leaf = is_present && is_last_spte(new_spte, level);
kvm_pfn_t new_pfn = spte_to_pfn(new_spte);
int ret = 0;
KVM_BUG_ON(was_present, kvm);
@@ -534,7 +533,7 @@ static int __must_check set_external_spte_present(struct kvm *kvm, tdp_ptep_t sp
* external page table, or leaf.
*/
if (is_leaf) {
ret = kvm_x86_call(set_external_spte)(kvm, gfn, level, new_pfn);
ret = kvm_x86_call(set_external_spte)(kvm, gfn, level, new_spte);
} else {
void *external_spt = get_external_spt(gfn, new_spte, level);

6
arch/x86/kvm/vmx/tdx.c
View File

@@ -1629,14 +1629,18 @@ static int tdx_mem_page_record_premap_cnt(struct kvm *kvm, gfn_t gfn,
}
static int tdx_sept_set_private_spte(struct kvm *kvm, gfn_t gfn,
enum pg_level level, kvm_pfn_t pfn)
enum pg_level level, u64 mirror_spte)
{
struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
kvm_pfn_t pfn = spte_to_pfn(mirror_spte);
/* TODO: handle large pages. */
if (KVM_BUG_ON(level != PG_LEVEL_4K, kvm))
return -EIO;
WARN_ON_ONCE(!is_shadow_present_pte(mirror_spte) ||
(mirror_spte & VMX_EPT_RWX_MASK) != VMX_EPT_RWX_MASK);
/*
* Read 'pre_fault_allowed' before 'kvm_tdx->state'; see matching
* barrier in tdx_td_finalize().