[PATCH v6 05/16] KVM: TDX: Pass size to reclaim_page()

isaku.yamahata
2023-11-07T15:13:58Z

From: Xiaoyao Li <xiaoyao.li@intel.com>

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@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
arch/x86/kvm/vmx/tdx.c | 27 +++++++++++++++------------
1 file changed, 15 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index a728175c4a6d..0fca863faeee 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -200,12 +200,13 @@ 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
@@ -214,7 +215,7 @@ 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
@@ -223,7 +224,7 @@ static void tdx_clear_page(unsigned long page_pa)
__mb();
}

-static int __tdx_reclaim_page(hpa_t pa)
+static int __tdx_reclaim_page(hpa_t pa, enum pg_level level)
{
struct tdx_module_args out;
u64 err;
@@ -241,17 +242,19 @@ static int __tdx_reclaim_page(hpa_t pa)
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));

return 0;
}

-static int tdx_reclaim_page(hpa_t pa)
+static int tdx_reclaim_page(hpa_t pa, enum pg_level level)
{
int r;

- r = __tdx_reclaim_page(pa);
+ r = __tdx_reclaim_page(pa, level);
if (!r)
- tdx_clear_page(pa);
+ tdx_clear_page(pa, KVM_HPAGE_SIZE(level));
return r;
}

@@ -265,7 +268,7 @@ 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))
+ if (tdx_reclaim_page(td_page_pa, PG_LEVEL_4K))
/*
* Leak the page on failure:
* tdx_reclaim_page() returns an error if and only if there's an
@@ -497,7 +500,7 @@ void tdx_vm_free(struct kvm *kvm)

if (!kvm_tdx->tdr_pa)
return;
- if (__tdx_reclaim_page(kvm_tdx->tdr_pa))
+ if (__tdx_reclaim_page(kvm_tdx->tdr_pa, PG_LEVEL_4K))
return;
/*
* TDX module maps TDR with TDX global HKID. TDX module may access TDR
@@ -510,7 +513,7 @@ void tdx_vm_free(struct kvm *kvm)
pr_tdx_error(TDH_PHYMEM_PAGE_WBINVD, err, NULL);
return;
}
- tdx_clear_page(kvm_tdx->tdr_pa);
+ tdx_clear_page(kvm_tdx->tdr_pa, PAGE_SIZE);

free_page((unsigned long)__va(kvm_tdx->tdr_pa));
kvm_tdx->tdr_pa = 0;
@@ -1597,7 +1600,7 @@ 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);
+ err = tdx_reclaim_page(hpa, level);
if (KVM_BUG_ON(err, kvm))
return -EIO;
tdx_unpin(kvm, pfn);
@@ -1630,7 +1633,7 @@ 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;
}
@@ -1742,7 +1745,7 @@ 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));
+ return tdx_reclaim_page(__pa(private_spt), PG_LEVEL_4K);

/*
* free_private_spt() is (obviously) called when a shadow page is being
--
2.25.1