2022-12-08 23:59:26

by Isaku Yamahata

Subject: [RFC PATCH v2 08/15] KVM: TDX: Pin pages via get_page() right before ADD/AUG'ed to TDs

From: Xiaoyao Li <[email protected]>

When kvm_faultin_pfn(), it doesn't have the info regarding which page level
will the gfn be mapped at. Hence it doesn't know to pin a 4K page or a
2M page.

Move the guest private pages pinning logic right before
TDH_MEM_PAGE_ADD/AUG() since at that time it knows the page level info.

Signed-off-by: Xiaoyao Li <[email protected]>
---
arch/x86/kvm/vmx/tdx.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 51b9e250437e..fad7413f7eab 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -1297,7 +1297,8 @@ static void tdx_measure_page(struct kvm_tdx *kvm_tdx, hpa_t gpa, int size)
}
}

-static void tdx_unpin(struct kvm *kvm, kvm_pfn_t pfn, int level)
+static void tdx_unpin(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn,
+ enum pg_level level)
{
int i;

@@ -1330,12 +1331,12 @@ static int tdx_sept_set_private_spte(struct kvm *kvm, gfn_t gfn,
if (likely(is_td_finalized(kvm_tdx))) {
err = tdh_mem_page_aug(kvm_tdx->tdr.pa, gpa, tdx_level, hpa, &out);
if (err == TDX_ERROR_SEPT_BUSY) {
- tdx_unpin(kvm, pfn, level);
+ tdx_unpin(kvm, gfn, pfn, level);
return -EAGAIN;
}
if (KVM_BUG_ON(err, kvm)) {
pr_tdx_error(TDH_MEM_PAGE_AUG, err, &out);
- tdx_unpin(kvm, pfn, level);
+ tdx_unpin(kvm, gfn, pfn, level);
return -EIO;
}
return 0;
@@ -1358,7 +1359,7 @@ static int tdx_sept_set_private_spte(struct kvm *kvm, gfn_t gfn,
* always uses vcpu 0's page table and protected by vcpu->mutex).
*/
if (KVM_BUG_ON(kvm_tdx->source_pa == INVALID_PAGE, kvm)) {
- tdx_unpin(kvm, pfn, level);
+ tdx_unpin(kvm, gfn, pfn, level);
return -EINVAL;
}

@@ -1376,7 +1377,7 @@ static int tdx_sept_set_private_spte(struct kvm *kvm, gfn_t gfn,
} while (err == TDX_ERROR_SEPT_BUSY);
if (KVM_BUG_ON(err, kvm)) {
pr_tdx_error(TDH_MEM_PAGE_ADD, err, &out);
- tdx_unpin(kvm, pfn, level);
+ tdx_unpin(kvm, gfn, pfn, level);
return -EIO;
} else if (measure)
tdx_measure_page(kvm_tdx, gpa, KVM_HPAGE_SIZE(level));
@@ -1405,7 +1406,7 @@ static int tdx_sept_drop_private_spte(struct kvm *kvm, gfn_t gfn,
err = tdx_reclaim_page(hpa, level, false, 0);
if (KVM_BUG_ON(err, kvm))
return -EIO;
- tdx_unpin(kvm, pfn, level);
+ tdx_unpin(kvm, gfn, pfn, level);
return 0;
}

@@ -1437,7 +1438,7 @@ static int tdx_sept_drop_private_spte(struct kvm *kvm, gfn_t gfn,
pr_tdx_error(TDH_PHYMEM_PAGE_WBINVD, err, NULL);
r = -EIO;
} else
- tdx_unpin(kvm, pfn + i, PG_LEVEL_4K);
+ tdx_unpin(kvm, gfn + i, pfn + i, PG_LEVEL_4K);
hpa += PAGE_SIZE;
}
return r;
--
2.25.1