On 7/26/2023 6:23 AM, isaku.yamahata@xxxxxxxxx wrote:
From: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
A 2MB large page can be tdh_mem_page_aug()'ed to TD directly. In this case,
it needs to reclaim and clear the page as 2MB size.
Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
---
arch/x86/kvm/vmx/tdx.c | 24 ++++++++++++++----------
1 file changed, 14 insertions(+), 10 deletions(-)
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 3522ee232eda..86cfbf435671 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -198,12 +198,13 @@ static void tdx_disassociate_vp_on_cpu(struct kvm_vcpu *vcpu)
smp_call_function_single(cpu, tdx_disassociate_vp_arg, vcpu, 1);
}
-static void tdx_clear_page(unsigned long page_pa)
+static void tdx_clear_page(unsigned long page_pa, int size)
{
const void *zero_page = (const void *) __va(page_to_phys(ZERO_PAGE(0)));
void *page = __va(page_pa);
unsigned long i;
+ WARN_ON_ONCE(size % PAGE_SIZE);
/*
* When re-assign one page from old keyid to a new keyid, MOVDIR64B is
* required to clear/write the page with new keyid to prevent integrity
@@ -212,7 +213,7 @@ static void tdx_clear_page(unsigned long page_pa)
* clflush doesn't flush cache with HKID set. The cache line could be
* poisoned (even without MKTME-i), clear the poison bit.
*/
- for (i = 0; i < PAGE_SIZE; i += 64)
+ for (i = 0; i < size; i += 64)
movdir64b(page + i, zero_page);
/*
* MOVDIR64B store uses WC buffer. Prevent following memory reads
@@ -221,7 +222,8 @@ static void tdx_clear_page(unsigned long page_pa)
__mb();
}
-static int tdx_reclaim_page(hpa_t pa, bool do_wb, u16 hkid)
+static int tdx_reclaim_page(hpa_t pa, enum pg_level level,
+ bool do_wb, u16 hkid)
{
struct tdx_module_output out;
u64 err;
@@ -239,8 +241,10 @@ static int tdx_reclaim_page(hpa_t pa, bool do_wb, u16 hkid)
pr_tdx_error(TDH_PHYMEM_PAGE_RECLAIM, err, &out);
return -EIO;
}
+ /* out.r8 == tdx sept page level */
+ WARN_ON_ONCE(out.r8 != pg_level_to_tdx_sept_level(level));
- if (do_wb) {
+ if (do_wb && level == PG_LEVEL_4K) {
I was wondering if it is better to add a WARN_ON_ONCE() to ensure level is
PG_LEVEL_4K instead of skipping it silently. But later, I found the
warning of
comparing out.r8 and level has guaranteed that there will be a warning
if there
is a mismatch between do_wb and level.
/*
* Only TDR page gets into this path. No contention is expected
* because of the last page of TD.
@@ -252,7 +256,7 @@ static int tdx_reclaim_page(hpa_t pa, bool do_wb, u16 hkid)
}
}
- tdx_clear_page(pa);
+ tdx_clear_page(pa, KVM_HPAGE_SIZE(level));
return 0;
}
@@ -266,7 +270,7 @@ static void tdx_reclaim_td_page(unsigned long td_page_pa)
* was already flushed by TDH.PHYMEM.CACHE.WB before here, So
* cache doesn't need to be flushed again.
*/
- if (tdx_reclaim_page(td_page_pa, false, 0))
+ if (tdx_reclaim_page(td_page_pa, PG_LEVEL_4K, false, 0))
/*
* Leak the page on failure:
* tdx_reclaim_page() returns an error if and only if there's an
@@ -474,7 +478,7 @@ void tdx_vm_free(struct kvm *kvm)
* while operating on TD (Especially reclaiming TDCS). Cache flush with
* TDX global HKID is needed.
*/
- if (tdx_reclaim_page(kvm_tdx->tdr_pa, true, tdx_global_keyid))
+ if (tdx_reclaim_page(kvm_tdx->tdr_pa, PG_LEVEL_4K, true, tdx_global_keyid))
return;
free_page((unsigned long)__va(kvm_tdx->tdr_pa));
@@ -1468,7 +1472,7 @@ static int tdx_sept_drop_private_spte(struct kvm *kvm, gfn_t gfn,
* The HKID assigned to this TD was already freed and cache
* was already flushed. We don't have to flush again.
*/
- err = tdx_reclaim_page(hpa, false, 0);
+ err = tdx_reclaim_page(hpa, level, false, 0);
if (KVM_BUG_ON(err, kvm))
return -EIO;
tdx_unpin(kvm, pfn);
@@ -1501,7 +1505,7 @@ static int tdx_sept_drop_private_spte(struct kvm *kvm, gfn_t gfn,
pr_tdx_error(TDH_PHYMEM_PAGE_WBINVD, err, NULL);
return -EIO;
}
- tdx_clear_page(hpa);
+ tdx_clear_page(hpa, PAGE_SIZE);
tdx_unpin(kvm, pfn);
return 0;
}
@@ -1612,7 +1616,7 @@ static int tdx_sept_free_private_spt(struct kvm *kvm, gfn_t gfn,
* already flushed. We don't have to flush again.
*/
if (!is_hkid_assigned(kvm_tdx))
- return tdx_reclaim_page(__pa(private_spt), false, 0);
+ return tdx_reclaim_page(__pa(private_spt), PG_LEVEL_4K, false, 0);
/*
* free_private_spt() is (obviously) called when a shadow page is being
